Program & Abstract Book

2nd International Workshop on Graphene and C3N4-Based Photocatalysts March 24-27, 2017, Wuhan University of Technology, Wuhan, China

Program & Abstract Book

Organized by Wuhan University of Technology Jianghan University Changsha University Supported by National Natural Science Foundation of China Applied Surface Science, Elsevier

http://IWGCP 2.do.am/

Wuhan, China

2nd International Workshop on Graphene and C3N4-Based Photocatalysts State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan, 430070, P.R. China Tel: 8627-87871029; Fax: 8627-87879468 Email: [email protected] Website: http://IWGCP2.do.am

Wuhan, China

※Contents※ Special Issue for IWGCP2 ................................................ 1 International Advisory Committee .................................. 2 Organizing Committee ..................................................... 3 Welcome Address .............................................................. 4 Layout of Symposium Locations ..................................... 5 Programs............................................................................ 6 List of Presentations ....................................................... 10 Abstracts Plenary Lectures ......................................................... 20 Keynote Lectures ........................................................ 28 Invited Lectures .......................................................... 42 Oral Lectures ............................................................... 58 Poster Presentations .................................................... 66 List of Authors ................................................................ 67

0

Wuhan, China

Special Issue for IWGCP2

There will be a special issue of Applied Surface Science dedicated to the IWGCP2 for which the theme is “Graphene and C3N4-based photocatalysts”. This journal has an impact factor of 3.15 (year 2015). Participants may submit their manuscripts for publication in this special issue, which will be peer reviewed according to the normal review practices of Applied Surface Science. The full paper submission is now available (Choose Article Type SI: IWGCP2 photocatalysis). The format of the manuscripts is the same as that used for submissions of a regular item to Applied Surface Science. Papers submitted to this special issue should describe but are not limited to: • Graphene-based composite photocatalysts • C3N4-based photocatalysts • Two-dimensional (2D) layered photocatalysts • Surface modification of photocatalysts • First-principles studies of photocatalysts • Photocatalytic water splitting for hydrogen and oxygen evolutions • Photocatalytic CO2 reduction to solar fuels • Environmental applications of photocatalysts • Dye-sensitized and perovskite solar cells • Surface science of photocatalysis and photoelectrocatalysis • All other photocatalytic materials Studies that focus on graphene, C3N4 and two-dimensional layered photocatalysts and their energy and environmental applications, will be given primary considerations. Brief summary of the special issue: ✓ Note that only full research papers or review papers of high quality can be accepted. ✓ In order to facilitate a timely publication schedule, the deadline for all papers to be submitted via Elsevier editorial system (EES) is 20 May, 2017, and the final decisions about acceptance of the submitted manuscripts will be made by 1 August, 2017. ✓ Guest editors: Professor Jiaguo Yu (Wuhan University of Technology, China) and Professor Mietek Jaroniec (Kent State University, USA)

1

Wuhan, China

International Advisory Committee Henrik Rudolph

Netherlands Defence Academy, Netherlands

Ib Chorkendorff

Technical University of Denmark, Denmark

Akihiko Kudo

Tokyo University of Science, Japan

Jae Sung Lee

Ulsan National Institute of Science and Technology, Korea

Zbigniew Sojka

Jagiellonian University, Poland

Wojciech Macyk

Jagiellonian University, Poland

Christos Trapalis

NCSR Demokritos, Greece

Tetsuro Majima

Osaka University, Japan

Hiromi Yamashita

Osaka University, Japan

Lianzhou Wang

University of Queensland, Australia

Xiwang Zhang

Monash University, Australia

Ki Tae Nam

Seoul National University, Korea

Gongxuan Lu

Lanzhou Institute of Chemical Physics, CAS, China

Gang Liu

Shenyang Institute of Metal Research, CAS, China

Swelm Wageh

King Abdulaziz University, Saudi Arabia

Ahmed Al-Ghamdi

King Abdulaziz University, Saudi Arabia

Gomathi Devi

Bangalore University, India

Jeffrey Chi-Sheng Wu

National Taiwan University, Taiwan

Jiyan Liu

Jianghan University, China

Muhammad Tahir

University of Technology, Malaysia

Shiying Zhang

Changsha University, China

Sharifah Bee Abd Hamid

University of Malaya, Malaysia

Jiaqian Qin

Chulalongkorn University, Thailand

Yi-jun Xu

Fuzhou University, China

Selvaraj Rengaraj

Sultan Qaboos University, Oman

2

Wuhan, China

Organizing Committee Chair: Co-chair:

Jiaguo Yu, Wuhan University of Technology, China Mietek Jaroniec, Kent State University, USA

Local Committee Chunhua Chen Difa Xu Rongan He Gaoke Zhang Yuanzhi Li Lizhi Zhang Tianyou Peng Ying Yu Huogen Yu Shaowen Cao Ke Fan Jun Zhang Chuanjia Jiang Kangle Lv Qin Li Longhui Nie Li Zhao

Jianghan University Changsha University Changsha University Wuhan University of Technology Wuhan University of Technology Central China Normal University Wuhan University Central China Normal University Wuhan University of Technology Wuhan University of Technology Wuhan University of Technology Wuhan University of Technology Wuhan University of Technology South-Central University for Nationalities South-Central University for Nationalities Hubei University of Technology Hubei University

3

Wuhan, China

Welcome Address Distinguished guests, ladies and gentlemen! It is my great honor and pleasure to open the 2nd International Workshop on Graphene and C3N4-based Photocatalysts (IWGCP2) here at the Wuhan University of Technology (WHUT), China. First of all, on behalf of the organizing Committee of IWGCP2, I am very glad to welcome all of you participating in this workshop. I am deeply grateful not only to the Wuhan University of Technology, National Natural Science Foundation of China (NSFC), Jianghan University and Changsha University but also to the companies including Beijing Perfectlight, ThermoFisher, LumaSense Technologies, Anhui Kemi, Beijing XiangHu, Zhenjiang Silver Jewelry, Instytut Fotonowy and others for supports and contributions for this workshop, which gather us here to give presentations, discuss research topics of mutual interests and facilitate scientific exchange. The purpose of this workshop is to provide an international forum for exchange of information, to identify technical problems and to establish directions for future research by appraising the recent technology trends and theoretical investigations on the Graphene and C3N4-based Photocatalysts and related materials through informative and exciting presentations. The main topics of this workshop include but are not limited to: • Graphene-based composite photocatalysts • C3N4-based photocatalysts • Two-dimensional (2D) layered photocatalysts • Surface modification of photocatalysts • First-principles studies of photocatalysts • Photocatalytic water splitting for hydrogen and oxygen evolutions • Photocatalytic CO2 reduction to solar fuels • Environmental applications of photocatalysts • Dye-sensitized and perovskite solar cells • Surface science of photocatalysis and photoelectrocatalysis • Other photocatalytic materials There are 6 plenary lectures, 12 keynote lectures, 14 invited lectures, 4 oral lectures and 107 posters in total. The scientific committee will also select 10 best posters during the workshop. The full papers after peer review will be published in a special issue “Graphene and C 3N4-based Photocatalysts” of the Applied Surface Science journal. Finally, I would like to thank all the invited speakers and foreign and domestic participants for presentations and attendance. Also, my thanks are extended to colleagues of the organizing committee, who nicely handled many complicated managing problems. I sincerely wish all participants to enjoy this workshop.

Prof. Jiaguo Yu FRSC Organizing Committee of the IWGCP2 State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology

4

Wuhan, China

Layout of Symposium Locations

5

Wuhan, China

2nd International Workshop on Graphene and C3N4-Based Photocatalysts Programs March 24 (Friday) Whole day, Registration (Vienna Hotel Jiedaokou Branch)

March 25 (Saturday) 08:20 Opening Address (Prof. Jiaguo Yu)

Session 1 Chairman: 08:30 PL1: 09:15 PL2:

Henrik Rudolph (Netherlands Defence Academy, Netherlands) Ib Chorkendorff (Technical University of Denmark, Denmark) Photo-electro-chemical water splitting and the making of renewable chemicals Tetsuro Majima (Osaka University, Japan) Visible and near-IR light responsible photocatalysts composited with 2D nanomaterials

10:00 Photo/Coffee Break

Session 2 Chairman: 10:30 KL1: 11:00 KL2: 11:30 IL1: 11:50 IL2:

Tetsuro Majima (Osaka University, Japan) Lizhi Zhang (Central China Normal University, China) Lianzhou Wang (University of Queensland, Australia) Semiconductor materials for bifunctional photoelectrochemical energy conversion Bin Liu (Nanyang Technological University, Singapore) Composite g-C3N4 nanostructures for efficient photocatalytic hydrogen evolution Rengaraj Selvaraj (Sultan Qaboos University, Oman) Metal sulfide nanostructured materials: an effective visible light active photocatalyst for the degradation of toxic organic pollutants Pichiah Saravanan (Indian Institute of Technology, India) Mechanistics characteristics of incorporated organic semiconductor with inorganic (gC3N4/SrTiO3) for improved solar light utilisation

12:10 Lunch (Shuntianlou Restaurant)

Session 3 Chairman: 14:00 KL3: 14:30 KL4:

15:00 IL3: 15:20 IL4:

Ib Chorkendorff (Technical University of Denmark, Denmark) Jeffrey Chi-Sheng Wu (National Taiwan University, Taiwan) Lizhi Zhang (Central China Normal University, China) Layered bismuth oxyhalide photocatalysts Ki Tae Nam (Seoul National University, Korea) Organic inorganic perovskites photocatalysis: dynamic equilibrium of methylammonium lead iodide in aqueous solution for hydrogen evolution Liqiang Jing (Heilongjiang University, China) Synthesis of efficient graphene- and C3N4-based photocatalysts Fan Dong (Chongqing Technology and Business University, China) New strategies to enhance the photocatalysis of g-C3N4: alkalis mediated vertical channel and size-dependent Bi metal deposition

6

Wuhan, China 15:40 IL5:

Tao He (National Center for Nanoscience and Technology, CAS, China) Visible-light driven photocatalytic CO2 reduction using g-C3N4 nanosheets/Fe MC heterogeneous catalysts

16:00 Coffee Break

Session 4 Chairman: 16:20 KL5: 16:50 IL6: 17:10 IL7: 17:30 IL8:

17:50 IL9:

Lianzhou Wang (University of Queensland, Australia) Ki Tae Nam (Seoul National University, Korea) Jeffrey Chi-Sheng Wu (National Taiwan University, Taiwan) Photo-reactor design of sunlight harvesting for solar H2 by water splitting Xintong Zhang (Northeast Normal University, China) Ultrasonic spray pyrolyzed TiO2/Keggin POMs microspheres for CO2 photoreduction Ying Yu (Central China Normal University, China) Copper and copper oxides based materials for CO2 photo(electro)chemical conversion to organic fuel Kangle Lv (South‐Central University for Nationalities, China) Fabrication of TiO2 nanorod assembly grafted rGO (rGO@TiO2-NR) hybridized flake-like photocatalyst Shaowen Cao (Wuhan University of Technology, China) Facet effect of metal cocatalyst on solar-to-fuel conversion over semiconductor photocatalysts

18:10 Perfectlight Dinner (Jiulong Restaurant)

March 26 (Sunday) Session 5 Chairman: 08:30 PL3: 09:15 PL4:

Jae Sung Lee (Ulsan National Institute of Science and Technology, Korea) Akihiko Kudo (Tokyo University of Science, Japan) Photocatalytic water splitting and CO2 reduction using metal oxide, sulfide materials, and reduced graphene oxide Mietek Jaroniec (Kent State University, USA) Tailoring morphology and porosity of graphene- and carbon nitride-based nanostructures

10:00 Coffee Break

Session 6 Chairman: 10:20 KL6:

10:50 KL7: 11:20 IL10: 11:40 IL11:

Christos Trapalis (NCSR Demokritos, Greece) Gang Liu (Institute of Metal Research, CAS, China) Gongxuan Lu (Lanzhou Institute of Chemical Physics, CAS, China) Enhanced water splitting via inhibition of hydrogen-oxygen recombination over graphene photocatalyst under visible light irradiation Yi-Jun Xu (Fuzhou University, China) On the way to efficient graphene-based composite photocatalysts for solar energy conversion Shurong Ma (Thermo Fisher Scientific Inc.) Raman spectroscopy and Raman imaging for assessing and studying catalytic materials Shengwei Liu (Sun Yat-sen University, China) Photocatalytic carbon cycling for controlling organic pollution and reducing CO2 emission

12:00 Lunch (Shuntianlou Restaurant)

7

Wuhan, China

Session 7 Akihiko Kudo (Tokyo University of Science, Japan) Gongxuan Lu (Lanzhou Institute of Chemical Physics, CAS, China) 14:00 KL8: Christos Trapalis (NCSR Demokritos, Greece) Alkaline Earth Modified g-C3N4 Nanocomposites for NOx Removal 14:30 KL9: Gang Liu (Institute of Metal Research, CAS, China) Controlling compositions and microstructures of carbon nitride for high photocatalytic activity 15:00 KL10: Tierui Zhang (Technical Institute of Physics and Chemistry, CAS, China) Alkali-assisted synthesis of nitrogen deficient graphitic carbon nitride with tunable band structures for efficient visible light-driven hydrogen evolution 15:30 IL12: Ji-Jun Zou (Tianjin University, China) O-doping and nanoporous graphitic carbon nitride for enhanced hydrogen evolution

Chairman:

15:50 Coffee Break

Session 8 Chairman: Christos Trapalis (NCSR Demokritos, Greece) 16:10 IL13: Guidong Yang (Xi’an Jiaotong University, China)

16:30 OL1:

16:45 OL2: 17:00 OL3:

Fish-scale structured g-C3N4 nanosheet with unusual spatial electron transfer property for high-efficiency photocatalytic hydrogen evolution Daimei Chen (China University of Geosciences, China) Preparation of graphene-photocatalyst hydrogel composite and its application for the removal of organic contaminant Quanjun Xiang (Huazhong Agricultural University, China) Ternary TiO2 nanosheets–graphene–CdSe quantum dots composite as a high efficient visible-light-driven photocatalyst Yongbing Xie (Institute of Process Engineering, CAS, China) WO3 catalysed visible light photocatalytic ozonation for wastewater treatment

17:15 Poster/rest 18:15 Dinner (Jiulong Restaurant) 20:00-22:00 Meeting with Editors

8

Wuhan, China

March 27 (Monday) Session 9 Chairman:

08:30 PL5: 09:15 PL6:

Mietek Jaroniec (Kent State University, USA) Hiromi Yamashita (Osaka University, Japan) Design of nanostructured photocatalysts for efficient hydrogen generation from carrier molecules Jae Sung Lee (Ulsan National Institute of Science and Technology, Korea) PEC-PV tandem cell for photoelectrochemical water splitting for solar hydrogen production

10:00 Coffee Break

Session 10 Chairman: Hiromi Yamashita (Osaka University, Japan) 10:20 KL11: Wojciech Macyk (Jagiellonian University, Polland) Do we know how to design a photocatalyst for CO2 reduction? 10:50 KL12: Xiwang Zhang (Monash University, Australia) Two-dimensional (2D) based photocatalysts for antimicrobial applications 11:20 IL14: Ming-Chung Wu (Chang Gung University, Taiwan) Photocatalytic hydrogen production of palladium nanoparticles decorated black TiO2 calcined in argon atmosphere 11:40 OL4: Qin Li (South-Central University for Nationalities, China) Effect of carbon materials on photocatalytic performance of metal sulfides for H2 production 11:55 OL5: Xin Li (South China Agricultural University, China) Constructing multi-functional metallic Ni interface layers in the g-C3N4 nanosheets/amorphous NiS heterojunctions for efficient photocatalytic H2 generation

12:10 Perfectlight Poster Awards & Closing Remarks (Prof. Mietek Jaroniec) 12:20 Lunch (Shuntianlou Restaurant) 14:00 Wuhan Tour

9

Wuhan, China

List of Presentations Plenary Lectures PL1: PL2: PL3:

PL4: PL5: PL6:

Photo-electro-chemical water splitting and the making of renewable chemicals Ib Chorkendorff, Bae Dowon, Brian Seger, Peter Vesborg, Thomas Pedersen, Ole Hansen Visible and near-IR light responsible photocatalysts composited with 2D nanomaterials Tetsuro Majima Photocatalytic water splitting and CO2 reduction using metal oxide, sulfide materials, and reduced graphene oxide Akihiko Kudo Tailoring morphology and porosity of graphene- and carbon nitride-based nanostructures Mietek Jaroniec Design of nanostructured photocatalysts for efficient hydrogen generation from carrier molecules Hiromi Yamashita, Kohsuke Mori, Yasutaka Kuwahara PEC-PV tandem cell for photoelectrochemical water splitting for solar hydrogen production Jae Sung Lee

Keynote Lectures KL1:

Semiconductor materials for bifunctional photoelectrochemical energy conversion Lianzhou Wang KL2: Composite g-C3N4 nanostructures for efficient photocatalytic hydrogen evolution Bin Liu KL3: Layered bismuth oxyhalide photocatalysts Lizhi Zhang KL4: Organic inorganic perovskites photocatalysis: dynamic equilibrium of methylammonium lead iodide in aqueous solution for hydrogen evolution Sunghak Park, Woo Je Chang, Ki Tae Nam KL5: Photo-reactor design of sunlight harvesting for solar H2 by water splitting Van Huy Nguyen, Duan-Xing Li, Jeffrey Chi-Sheng Wu KL6: Enhanced water splitting via inhibition of hydrogen-oxygen recombination over graphene photocatalyst under visible light irradiation Gongxuan Lu KL7: On the way to efficient graphene-based composite photocatalysts for solar energy conversion Yi-Jun Xu KL8: Alkaline earth modified g-C3N4 nanocomposites for NOx removal Ilias Papailias, Tatiana Giannakopoulou, Nadia Todorova, Sofia Karapati, Christos Trapalis KL9: Controlling compositions and microstructures of carbon nitride for high photocatalytic activity Gang Liu KL10: Alkali-assisted synthesis of nitrogen deficient graphitic carbon nitride with tunable band structures for efficient visible light-driven hydrogen evolution Huijun Yu, Run Shi, Tierui Zhang KL11: Do we know how to design a photocatalyst for CO2 reduction? Wojciech Macyk, Joanna Kuncewicz, Marcin Kobielusz, Tomasz Baran, Szymon Wojtyła KL12: Two-dimensional (2D) based photocatalysts for antimicrobial applications Xiangkang Zeng, Gen Wang, Zheng Xin, Xiwang Zhang

10

Wuhan, China

Invited Lectures IL1:

IL2:

IL3: IL4:

IL5:

IL6: IL7:

IL8:

IL9: IL10: IL11: IL12: IL13:

IL14:

Metal sulfide nanostructured materials: an effective visible light active photocatalyst for the degradation of toxic organic pollutants Rengaraj Selvaraj Mechanistics characteristics of incorporated organic semiconductor with inorganic (gC3N4/SrTiO3) for improved solar light utilisation Kah Hon Leong, Lan Ching Sim, Pichiah Saravanan, Detlef Bahnemann Synthesis of efficient graphene- and C3N4-based photocatalysts Yang Qu, Liqiang Jing New strategies to enhance the photocatalysis of g-C3 N4: alkalis mediated vertical channel and size-dependent Bi metal deposition Fan Dong, Wanglai Cen, Guangming Jiang, Jieyuan Li, Wen Cui, Ting Xiong Visible-light driven photocatalytic CO2 reduction using g-C3N4 nanosheets/Fe MC heterogeneous catalysts Lin Lin, Xuehua Zhang, Tao He Ultrasonic spray pyrolyzed TiO2/Keggin POMs microspheres for CO2 photoreduction Changhua Wang, Han Zheng, Xintong Zhang, Yichun Liu Copper and copper oxides based materials for CO 2 photo(electro)chemical conversion to organic fuel Luo Yu, Xin Ba, Guodong Shi, Yanfang Li, Wenpei Zhang, Ying Yu Fabrication of TiO2 nanorod assembly grafted rGO (rGO@TiO2-NR) hybridized flake-like photocatalyst Kangle Lv, Shun Fang, Lingling Si, Wingkei Ho Facet effect of metal cocatalyst on solar-to-fuel conversion over semiconductor photocatalysts Shaowen Cao Raman spectroscopy and Raman imaging for assessing and studying catalytic materials Shurong Ma, Ying Xie, Yanliang Zhang Photocatalytic carbon cycling for controlling organic pollution and reducing CO 2 emission Shengwei Liu, Jiaguo Yu O-doping and nanoporous graphitic carbon nitride for enhanced hydrogen evolution Jing-Wen Zhang, Ji-Jun Zou Fish-scale structured g-C3N4 nanosheet with unusual spatial electron transfer property for highefficiency photocatalytic hydrogen evolution Bo Lin, Hua An, Xiaoqing Yan, Tianxi Zhang, Jinjia Wei, Guidong Yang Photocatalytic hydrogen production of palladium nanoparticles decorated black TiO 2 calcined in argon atmosphere Yin-Hsuan Chang, Kai-Chi Hsiao, Po-Yeh Wu, Shun-Hsiang Chan, Ming-Chung Wu

Oral Lectures OL1:

OL2:

OL3: OL4:

Preparation of graphene-photocatalyst hydrogel composite and its application for the removal of organic contaminant Daimei Chen Ternary TiO2 nanosheets–graphene–CdSe quantum dots composite as a high efficient visiblelight-driven photocatalyst Yang Li, Quanjun Xiang WO3 catalysed visible light photocatalytic ozonation for wastewater treatment Jin Yang, Yongbing Xie, Hongbin Cao Effect of carbon materials on photocatalytic performance of metal sulfides for H 2 production Yang Xia, Qin Li, Kangle Lv, Mei Li

11

Wuhan, China OL5:

Constructing multi-functional metallic Ni interface layers in the g-C3N4 nanosheets/amorphous NiS heterojunctions for efficient photocatalytic H2 generation Jiuqing Wen, Jun Xie, Xiaobo Chen, Xin Li

Poster Presentations PP1: PP2:

PP3: PP4: PP5: PP6: PP7:

PP8: PP9: PP10:

PP11: PP12:

PP13:

PP14:

PP15:

PP16:

PP17:

ZnO nanoflowers with single crystal structure towards enhanced gas sensing and photocatalysis Dan Wang, Sha Zhang, Changchao Jia, Ping Yang, Xin Cheng Enhanced performance in perovskite solar cells via bromide ion substitution and ethanol treatment Bingjie Feng, Jun Zhang, Yang Xu, Zhaosong Li, Hao Wang Template-free fabrication of hierarchical macro/mesoporous SnS 2/TiO2 composites Gaopeng Dai, Shilong Li, Zhou Huan, Cong Pan, Suqin Liu Ionic liquid-facilitated synthesis and photocatalytic activity of TiO 2/graphene composite hydrogel Ruirui Liu, Zhijiang Ji SiO2-VO2 composite membrane with super hydrophobic and energy saving function Chao Wang, Li Zhao, Zihui Liang, Binghai Dong, Zuxun Xu, Li Wan, Shimin Wang Ni1-xFexOOH modified RGO/TiO2 for efficient photoelectrochemical water oxidation Xiaofan Zhang, Weiqian Kong, Baocheng Yang Metal-organic framework g-C3N4/MIL-53(Fe) heterojunctions with enhanced photocatalytic activity for Cr(VI) reduction under visible light Wenyuan Huang, Ning Liu, Yang Yang, Xiaodong Zhang, Minghong Wu, Liang Tang Effects of graphene doping amount on photocatalytic properties of MIL-88A(Fe) Ning Liu, Wenyuan Huang, Pin Tao, Xiaodong Zhang, Liang Tang, Minghong Wu The graphitic-C3N4 based composites: Synthesis and properties Jiali Lv, Jinfeng Zhang, Kai Dai Extending visible light absorption effectively with broad spectrum sensitizer for improvement of H2 evolution of in-situ Cu/g-C3N4 nanocomponent Piyong Zhang, Ting Song, Tingting Wang, Heping Zeng B doped C3N4 modified TiO2 nanorods for efficient photoelectrochemical water oxidation Weiqian Kong, Xiaofan Zhang, Baocheng Yang, Shouren Zhang Progressive design of plasmonic metal-semiconductor ensemble toward improved vis-NIR-driven solar-to-chemical conversion Chuang Han, Quan Quan, Yi-Jun Xu Facile synthesis and characterization of N-doped TiO2/C nanocomposites with enhanced visiblelight photocatalytic performance Tiekun Jia, Fang Fu, Dongsheng Yu, Jianliang Cao, Guang Sun Fabrication of luminescent graphitic C3N4 nanosheets (g-C3N4 NS) and reduced graphene oxide (rGO) composite structure towards efficient photocatalytic activity Changchao Jia, Yumeng Liu, Ping Yang Hierarchical double-shelled zinc nickel oxide hollow spheres derived from metal-organic frameworks as efficient photocatalysts for the degradation of Rhodamine B Ying Zhang, Jiabin Zhou Gold nanoparticle modified graphitic carbon nitride films with enhanced photoelectrochemical performance Xiaowei Lv, Lei Pan, Yan Shen A robust self-sacrificial strategy to construct g-C3N4/LaCO3OH heterostructures with high photocatalytic NOx removal efficiency Zhenyu Wang, Yu Huang, Junji Cao

12

Wuhan, China PP18: Chemical etching fabrication of mesoporous Bi2O3@Bi nanospheres with high visible-lightactivity Peng Zhang, Yu Huang, Junji Cao PP19: Preparation of g-C3N4 based semiconductor composites with highly-efficient photocatalytic activity Yanbiao Shi, Qizhao Wang PP20: The study of ZnO samples synthesized via simple solvothermal method and photocatalytic properties Yu Liu, Haixia Liu PP21: Synthesis and photocatalytic activity of flower-like anatase TiO2 with nanosheets Kerui Fan, Haixia Liu PP22: In situ prepared Au nanoparticles on ZnO/g-C3N4 nanocomposites as plasmonic photocatalysts for significantly enhanced hydrogen production Jian Zeng, Heping Zeng PP23: Fabrication of three dimensional CNT-graphene/BiOI nanostructure electrode in photoactivated fuel cell to recover energy from organic pollutants Lingling Hu, Chun He, Jiawei Zeng, Yajing Huang, Wenjun Xu, Zhuoyan He, Xiuqin Tan PP24: Highly efficient photocatalytic hydrogen generation on CdS using graphene and MoS 2 nanosheets as cocatalysts Liwen He, Bolin Zhu, Yan Liu, Peipei Liu, Bizhou Lin PP25: Molybdenum phosphide modified carbon nitride as an efficient photocatalyst for hydrogen generation Zhen Peng, Wei Liu, Yanhui Fu, Shufang Chang, Hua Tang PP26: Designing metal-free, robust, regenerable 3D graphene-organics aerogels with high and stable photosensitization efficiency Min-Quan Yang, Yi-Jun Xu PP27: The effect of the calcination temperature to the visible light photocatalytic activity of direct contact Z-scheme g-C3N4-TiO2 Juan Li, Min Zhang, Xuan Li, Qiuye Li, Jianjun Yang PP28: Green synthesis of silver nanoparticle - reduced graphene oxide using Psidium guajava and its application in SERS for the detection of methylene blue Prajwal Chettri, V. S. Vendamani, Ajay Tripathi, Manish Kumar Singh, Anand P. Pathak, Archana Tiwari morphology of cuprous oxide nanoparticles: ionic liquid-assisted synthesis and PP29: Various photocatalytic performance

Lulu Liu, Yubo Xie, Yang Xuan, Kezhen Qi PP30: The exfoliation of Fe2O3 interlayered bulk g-C3N4 to ultrathin g-C3N4 with enhanced photocatalytic performance Yongning Ma, Enzhou Liu, Juan Li, Xiaoyun Hu, Jun Fan PP31: In situ construction of g-C3N4/TiO2 heterojunction film with enhanced light-harvesting ability for efficient photocatalysis Chao Pan, Yongning Ma, Jun Wan, Enzhou Liu, Xiaoyun Hu, Jun Fan PP32: Enhanced solar-driven hydrogen evolution using all-solid-state Z-scheme photocatalyst with carbon nanotubes as electron mediator Boon-Junn Ng, Lutfi Kurnianditia Putri, Pooria Pasbakhsh, Siang-Piao Chai PP33: Room temperature in-situ fabrication of direct Z-scheme Bi2O3/g-C3N4 composite photocatalyst and its enhanced photocatalytic activity Rongan He, Jiaqian Zhou, Huiqing Fu, Difa Xu, Shiying Zhang, Yanhua Li PP34: Preparation of nanostructured lamellar materials in molten salts Jing Zhou, Wei Xiao, Dihua Wang PP35: Molten-salt-assisted preparation of ultrathin/ultrafine lamellar nanostructured materials Chen Zeng, Ni Li, Teng Lv, Jing Zhou, Wei Xiao

13

Wuhan, China PP36: Reduced graphene oxide in Ag2CO3 photocatalyst: a double-edged sword to photocatalytic activity and cycling stability Wenguang Wang, Yuan Liu, Haiyan Zhang, Yannan Qian, Zuchen Guo PP37: A novel ternary Ag/CeVO4/g-C3N4 nanocomposite with enhanced visible-light photocatalytic activity for organic dye decomposition Jie Ren, Yanze Wu, Jianmei Pan, Hua Tang, Xiaonong Cheng, Xuehua Yan PP38: Enhanced visible-light photo-oxidation of nitric oxide using bismuth-coupled graphitic carbon nitride composite heterostructures Yuhan Li, Kangle Lv, WingKei Ho, Zaiwang Zhao, Yu Huang PP39: Effect of carbon-dots modification on the structure and photocatalytic activity of g-C3N4 Shun Fang, Yang Xia, Kangle Lv, Qin Li, Jie Sun, Mei Li PP40: Hybridization of rutile TiO2 (rTiO2) with g-C3N4 quantum dots (CN QDs): An efficient visiblelight-driven Z-scheme hybridized photocatalyst Yuhan Li, Kangle Lv, Wingkei Ho, Fan Dong PP41: Effect of mesoporous g-C3N4 substrate on catalytic oxidation of CO over Co3O4 Heng Yang, Kangle Lv, Junjiang Zhu PP42: Photocatalytic hydrogen production from methanol over Nd/TiO 2 Martin Reli, Miroslava Edelmannová, Ivana Troppová, Libor Čapek, Kamila Kočí PP43: Copper and platinum doped titania for photocatalytic reduction of carbon dioxide Nela Ambrožová, Martin Reli, Marcel Šihor, Miroslava Edelmannová, Ivana Troppová, Jaroslav Lang, Anna Rokicińska, Piotr Kuśtrowski, Jeffrey C.S. Wu, Kamila Kočí PP44: Unconventionally prepared TiO2/g-C3N4 photocatalysts for photocatalytic decomposition of nitrous oxide Ivana Troppová, Martina Šindlářová, Marcel Šihor, Martin Reli, Michal Ritz, Petr Praus, Kamila Kočí PP45: Microwave-assisted hydrothermal synthesis of anatase TiO2 single crystals exposing highpercentage {001} active facets and their photocatalytic properties Huifen Tong, Gang Chang, Pai Li, Yunbin He PP46: Enhanced performances of dye-sensitized solar cells based on Au/Ag-hybrid TiO2 plasmonic nanocomposites Huili Ran, Mengjun Ma, Jiajie Fan, Guosheng Shao PP47: Numerical investigation of CuO based heterojunction solar cells Kemeng Tong, Jinsheng Zhai, Jiajie Fan, Guosheng Shao PP48: Effects of post-annealing on structural, photoluminescence, optical, electrical properties of CuO thin films Zhenzhen Li, Jiajie Fan, Guosheng Shao PP49: Black phosphorus/TiO2 composite photoanode with enhanced photoelectrical performance Jia Song, Jing Wang, Xiaoyu Lin, Jingfu He, Hualei Liu, Yongpeng Lei, Zengyong Chu PP50: Constructing multi-functional metallic Ni interface layers in the g-C3N4 nanosheets/amorphous NiS heterojunctions for efficient photocatalytic H2 generation Jiuqing Wen, Jun Xie, Xiaobo Chen, Xin Li PP51: Copper nanoparticles interspersed MoS2 nanoflowers with enhanced efficiency for CO2 electrochemical reduction to fuel Guodong Shi, Ying Yu PP52: Exploring the structure of the polymeric g-C3N4 via the nanoribbon Hong-Zhang Wu, Zhenling Wang PP53: Preparation and application of g-C3N4-NiO-Co3O4 hybrid nanocomposites with an effective photoelectrochemical property for analysis of tetrabromobisphenol-A Yi Liu, Jing Zou, Wanyun Gong, Sheng Zhang, Xin Zhou, Yanjuan Sun, Shengli Wu PP54: 2D Clay/rGO ordered heterostructures dispersible in water via a one-step green route E.C. Vermisoglou, T. Giannakopoulou, N. Todorova, T. Vaimakis, D. Petridis, C. Trapalis

14

Wuhan, China PP55: Graphene and g-C3N4 based photocatalysts for NO oxidation: A Review Aspasia Nikokavoura, Christos Trapalis PP56: Photoreduction of electrochemically deposited graphene films: Solar vs UV and pre- vs postphotoreduction Tatiana Giannakopoulou, Nadia Todorova, Christos Trapalis PP57: De-NOx activity of TiO2/graphene photocatalysts: “In-situ” vs “ex-situ” synthesized TiO2 N. Todorova, A. Trapalis, T. Giannakopoulou, I. Papailias, C. Trapalis PP58: Synthesis of g-C3N4/BiPO4 with core-shell structure by one-step hydrothermal method for efficient decomposition of dimethyl phthalate in aqueous solution Yan Wang, Ying Yu PP59: MoS2 nanosheet decorated porous SnO2 nanofibers for enhanced catalytic reduction of 4nitrophenol Zhenwei Zhang, Xiuqing Qiao, Dongfang Hou, Dongsheng Li PP60: Visible-light enhanced photoelectrocatalytic ethanol oxidation based on two dimensional Pt-BiOI electrode Chunyang Zhai, Jiayue Hu, Mingjuan Sun, Mingshan Zhu PP61: High photocatalytic performance of Ag/TiO2 nanofibers: photodegradation of organic dye and photocatalytic H2 generation Ting-Han Lin, Po-Yeh Wu, Yin-Hsuan Chang, Ming-Chung Wu PP62: Copper doping effects on photocatalytic properties of TiO 2 NFs Kuo-Ping Chiang, Po-Yeh Wu, Yin-Hsuan Chang, Ting-Han Lin, Ming-Chung Wu PP63: In situ growth of WO3 nanoplates on g-C3N4 with enhanced photocatalytic performance Bo Chai, Mengqiu Xu, Juntao Yan, Chunlei Wang PP64: Immobilization and photocatalytic activity research of highly dispersed magnetic Fe3O4 on TiO2 Qiuhong Liu, Qiong Sun PP65: Photo-reactivity and mechanism of g-C3N4 and Ag co-modified Bi2WO6 microsphere under visible light irradiation Xiaoping Xiao, Ting Zhang, Jianhong Wei PP66: Influence of the anti-solvents on the performance of the methylammonium lead triiodide perovskite solar cells Bo-Yi Liou, Kun-Mu Lee PP67: Pt-doped titanate nanotube/graphene oxide nanocomposites: preparation, photodegradation and flame retardancy Guangya Liu, Bin Sang, Zhiwei Li, Zhijun Zhang PP68: Enhanced the visible-light photocatalytic performance of g-C3N4/Ag by Fe(III) cocatalysts modification Yanhui Fu, Wei Liu, Hua Tang PP69: A facile solvothermal method to produce two-dimensional layered SnS2 with efficient photocatalytic activity under visible light Juan Feng, Jianglong Mu, Hui Miao, Enzhou Liu, Jun Fan, Xiaoyun Hu PP70: Novel Z-scheme visible-light-driven porous 3D S-doped ZnO/g-C3N4 heterostructures with enhanced photocatalytic performance Fengyu Tian, Fan Tang, Dongfang Hou, Xiuqing Qiao, Dongsheng Li PP71: Facile fabrication of noble metal particles modified mesoporous g-C3N4 for efficient catalytic reduction of 4-NP Fengyu Tian, Tang Fan, Dongfang Hou, Xiuqing Qiao, Dongsheng Li PP72: Photoassisted oxygen reduction reaction on mpg-C3N4: The effects of elements doping on the performance of ORR Qiuchen He, Feng Zhou, Su Zhan, Naibao Huang, Yu Tian

15

Wuhan, China PP73: Mechanisms on the enhanced sterilization performance of fluorocarbon resin composite coatings modified by Bi2MoO6/g-C3N4 under the visible-light Yu Tian, Feng Zhou, Su Zhan, Zhenyu Zhu, Qiuchen He PP74: The photocatalytic activity of g-C3N4/Sn3O4 composites under visible-light Fan Wu, Feng Zhou, Su Zhan, Qiuchen He, Yu Tian, Naibao Huang PP75: Study on the bactericidal performance of graphene/TiO2 composite photocatalyst in the coating of PEVE Zhenyu Zhu, Feng Zhou, Yu Tian, Su Zhan, Heqiu Chen, Naibao Huang PP76: Synergistic effect of graphene as electron-transfer mediator and Ni(II) as oxygen-reduction active site for enhanced H2-production performance of TiO2 Ping Wang, Chaoying Zhang, Yanyan Liu, Lingna Hu and Huogen Yu PP77: Facile hydrothermal synthesis of carbon dots modified g-C3N4 for enhanced photocatalytic H2evolution performance Xuefei Wang, Jingjing Cheng, Huogen Yu PP78: Highly efficient dual cocatalyst-modified TiO2 photocatalyst: rGO as electron-transfer mediator and MoSx as H2-evolution active site Xuefei Wang, Yongan Li, Huogen Yu PP79: Preparation, characterization and enhanced visible-light photocatalytic activity of g-C3N4/BiOBr heterojunction nanocomposites with 2D intercalated structure Chunhua Cao, Chunhua Chen, Liang An, Zhihua Xu PP80: Coral-like polyaniline/TiO2 porous micro-composite compound: Facile preparation, characterization and enhanced visible-light-driven photocatalytic activity Liang An, Yong Xu, Zhihua Xu, Yang Cheng, Guanghui Wang PP81: A new understanding of the photocatalytic mechanism of the direct Z-scheme g-C3N4/TiO2 heterostructure Jianjun Liu, Bei Cheng, Jiaguo Yu PP82: Double Z-scheme ZnO/ZnS/g-C3N4 ternary structure for efficient photocatalytic H2 production Zhifang Dong, Yan Wu PP83: Nitrogen doped graphene as a novel photocatalyst for photocatalytic reduction elimination of UO22+ pollutant Xi Wu, Changhai Lu, Shaoqing Song PP84: Enhancement the photocatalytic activity of semiconductor oxide modified with g-C3N4 Yajun Wang, Juan Chen, Qiaohuan Wu, Yan Li, Tie Fu, Guiyuan Jiang, Zhen Zhao PP85: Reduction of NO3－ in aqueous solutions via Photocatalysis by Pt-Cu Nanoalloy particles supported TiO2 microsphere as catalyst Fuying Li, Yu Niu, Zizhong Zhang, Xuxu Wang PP86: Constructing 2D layered MoS2 nanosheets-modified Z-scheme TiO2/WO3 nanofibers ternary nanojunction with enhanced photocatalytic activity Jiangtao Zhao, Peng Zhang, Jiajie Fan, Hongqing Gao, Junhua Hu, Guosheng Shao PP87: Enhanced visible-light photocatalytic H2-generation activity of carbon/g-C3N4 nanocomposites prepared by two-step thermal treatment Quanlong Xu, Chuanjia Jiang, Bei Cheng, Jiaguo Yu PP88: Effect of anatase TiO2 {001} facets on catalytic oxidation of formaldehyde at room temperature Xinyang Li, Yue Li PP89: Preparation of CdS-g-C3N4 composite photocatalyst by membrane technology with enhanced hydrogen production activity Xiaoguang Wang, Shihao Gong,Yuan Feng, Yu Fang, Li Zhang PP90: Synthesis of bismuth oxide using extraction-precipitation stripping method and its photocatalytic properties Jun Chen, Jing Zhan

16

Wuhan, China PP91: Synthesis of g-C3N4-CdS composites with enhanced photocatalytic properties and analysis of cadmium residue in X-3B dye water samples Shihao Gong, Li Zhang, Xiaoguang Wang, Yu Fang, Xu Yang PP92: Internal electric field induced direct Z-scheme g-C3N4/SnS2 photocatalyst with highly efficient visible-light photocatalytic CO2 reduction activity Tingmin Di, Jiaguo Yu PP93: Hierarchical porous O-doped g-C3N4 with enhanced photocatalytic CO2 reduction activity Junwei Fu, Bicheng Zhu, Chuanjia Jiang, Bei Cheng, Wei You, Jiaguo Yu PP94: Synthesis and properties of SnO2/TS-1 for photocatalytic dye degradation Ri-Meng Zhan, Ming-Xia Liu, Ze-Tang Ou, Zheng-De Tan PP95: Synthesis of novel hierarchical β-Bi2O3/g-C3N4 Z-scheme photocatalyst with enhanced visible light photocatalytic activity Liping Zhang, Zhenzhong Xiong, Guohong Wang PP96: Synthesis of g-C3N4 nanosheets with a large surface area for enhanced visible-light photocatalytic activity Qingchuan Xu, Xiaoming Zhang, Guohong Wang PP97: g-C3N4 nanosheets wrapped TiO2 nanoflower composites with an enhanced visible light photocatalytic activity for Rhodamine B degradation Juan Wang, Guohong Wang PP98: Effects of calcining temperature on microstructure and photocatalytic activity of TiO 2/g-C3N4 heterojunction photocatalysts Lianying Lu, Guohong Wang, Min Zou, Juan Wang PP99: Adsorption of CO2 on two-dimensional non-metal layer materials investigated by first-principle calculation Bicheng Zhu, Jiaguo Yu PP100: Noble metal-free NiS modified ZnIn2S4 with enhanced photocatalytic activity for selective oxidation of aromatic alcohols to aromatic aldehydes Jinfeng Zhang, Li Su, Shifu Chen, Kai Dai PP101: Extremely efficient full solar spectrum light driven thermocatalysis for benzene purification promoted by a novel photoactivation on ramsdellite MnO 2 hollow spheres Yi Yang, Yuanzhi Li, Min Zeng, Mingyang Mao, Xiujian Zhao PP102: Novel synergetic effect on benzene photothermocatalytic degradation of anatase TiO 2 nanosheets with dominant {001} facets Lu Ren, Qian Zhang, Yuanzhi Li PP103: Enhancement of photocatalytic hydrogen production on covalent triazine-based under visible light irradiation framework Qianqian Jiang, loaded Jinhong by MoS Bi, Liuyi Li,visible Shijinglight Liang, irradiation Ling Wu 2 under Qianqian Jiang, of Jinhong Bi, Liuyi Li,g-C Shijing Liang, Ling PP104: In situ growth dopamine on the N surface with Wu enhanced visible light photocatalytic 3 4 performance Pengfei Xia, Jiaguo Yu Yu Pengfei Xia,Mingjin MingjinLiu, Liu, Jiaguo PP105: Novel hierarchical ZnO & graphene composites with highly efficient visible-light photocatalytic activity

Linyu Zhu, Hong Li PP106: Significant enhancement of the photoelectrochemical activity of WO 3 nanoflakes by carbon quantum dots decoration

Weina Shi, Xiaofan Zhang, Jeremie Brillet, Dekang Huang, Man Li, Mingkui Wang, Yan Shen PP107: a* Constructing ultrathin carbon nitride nanosheets based composites with enhanced photocatalytic performance

Zili Xu, Min Xu, Yajuan Ma, Kannusamy Pandiselvi, Tao Li, Jingyu Wang PP108: The application of heterostructured SrTiO3-TiO2 nanotube arrays in dye-sensitized solar cells Yong Hong, Qiuhong Liu, Qiong Sun

17

Wuhan, China PP109: One-pot synthesis of ternary zero-valent iron/ phosphotungstic acid /g-C3N4 composite and its high performance for removal of arsenic(V) from water Chunhua Chen, Jia Xu, Zhihua Yang, LiZhang, Chunhua Cao, Zhihua Xu, Jiyan Liu PP110: Preparation of Ag2O/g‑C3N4 with enhanced visible-light photocatalytic activities Jie Wang, Yi Zhang, Longhui Nie PP111: Insight into the origin of boosted photosensitive efficiency of graphene from the synergetic theory and experiment study Kang-Qiang Lu, Nan Zhang, and Yi-Jun Xu PP112: Enhanced visible light photocatalytic degradation and antimicrobial performance of porous gC3N4 nanosheets Jing Xu, Na Ta, Qiuzhu Gao, Zhouping Wang PP113: Detoxification of zearalenone from corn oil by functionalized GO adsorption Xiaojuan Bai, Changpo Sun, Xiaohong Luo, Yangying Han

18

Wuhan, China

19

Wuhan, China

Plenary Lectures

20

Wuhan, China

21

Wuhan, China

Plenary Lecture PL1

Photo-electro-chemical water splitting and the making of renewable chemicals Ib Chorkendorff1, Bae Dowon1, Brian Seger1, Peter Vesborg1, Thomas Pedersen2, Ole Hansen2 1

Surfcat, DTU Physics; 2 DTU Nanotech, Technical University of Denmark, Kgs Lyngby, 2800, Denmark; E-mail: [email protected]

Abstract: Hydrogen is the simplest solar fuel to produce and in this presentation we shall give a short overview of the pros and cons of various tandem devices [1,2]. The large band gap semiconductor needs to be in front, but apart from that we can choose to have either the anode in front or back using either acid or alkaline conditions. Since most relevant semiconductors are very prone to corrosion the advantage of using buried junctions and using protection layers offering shall be discussed [3-5]. In particular we shall show how doped TiO2 is a very generic protection layer for both the anode and the cathode [6]. Next we shall discuss the availability of various catalysts for being coupled to these protections layers and how their stability and amount needed may be evaluated [7, 8, 9]. Examples of half-cell reaction using protection layers for both cathode and anode will be discussed though some of recent examples both under both alkaline and acidic conditions. Notably NiO x promoted by iron is a material that is transparent, providing protection, and is a good catalyst for O2 evolution [10]. Finally we shall also discuss the possibility of making high energy density fuels by hydrogenation of CO2 instead of hydrogen evolution [11]. We shall give a brief status of what limits our current catalysts today and discuss the way [12].

Keywords: Water splitting • Hydrogen • Tandem cells • Solar fuels • CO2 Hydrogenation [1] A. B. Laursen et al., Energy & Environ. Science 5 5577 (2012) [2] B. Seger et al. Energy & Environ. Science 7 2397 (2014) [3] B. Seger, et al. Angew. Chem. Int. Ed., 51 9128 (2012) [4] B. Seger, et al., JACS 135 1057 (2013) [5] B. Seger, et al., J. Mater. Chem. A, 1 (47) 15089 (2013) [6] B. Mai et al. J. Phys. Chem. C 119 15019 (2015) [7] R. Frydendal, et al. Chem.Elec.Chem 1 2075 (2014). [8] E. A. Paoli, et al. Chemical Science, Chemical Science, 6 190 (2015) [9] E. Kemppainen et al. Energy & Environmental Science, 8 2991 (2015) [10] B. Mei, et al. J. Phys. Chem. Lett. 5 1948 (2014) [11] A. Verdaguer-Casadevall et al. J. Am. Chem. Soc. 137 9808 (2015) [12] E. Z. W She, et al. SCIENCE (2017) 355 DOI:10.1126/science.aad4998

22

Wuhan, China

Plenary Lecture PL2

Visible and near-IR light responsible photocatalysts composited with 2D nanomaterials Tetsuro Majima The Institute of Scientific and Industrial Research, Osaka University, Mihogaoka 8-1, Ibaraki, Osaka, Japan [email protected]

Abstract: Hydrogen (H2) is a zero-carbon emission fuel, and is forecast to be an ideal source of energy in the future. In the past decades, great efforts have been devoted to realize efficient solar-tohydrogen (STH), since the first report of photoelectrochemical splitting of water into H 2 and O2 in 1972. Although H2 can be produced from direct splitting of water using semiconductor photocatalysts under solar light irradiation, the present energy conversion efficiency of STH is too low for the technology to be economically sound. The main barriers are the rapid charge recombination as well as no absorption of traditional semiconductors such as TiO2 in the visible and near-infrared (NIR) regions. In view of solar energy utilization, the search for suitable materials as photocatalysts that not only can harvest the broad wavelength solar light, from UV to near-infrared (NIR) region, but also can achieve high efficient solar-to-hydrogen conversion is one of the most challenging missions. Recently, among the numerous photocatalysts, layer-structured semiconductors have received extensive attention owing to their layered structures which separate out the H2 and O2 evolution sites. For example, perovskite semiconductors such as La2Ti2O7 (LTO) were found to be alternative photocatalysts for water splitting due to their unique 2D perovskite layered structure and high stabilities. However, similar to above traditional semiconductors, the wide band gap (3.4 eV) limits light harvesting in the UV light region. Although gold nanoparticlesmodified TiO2 exhibited a broad absorption from UV to far visible region (250~800 nm), the poor energy conversion efficiency under NIR light irradiation (ca. 44% of NIR light in our incoming solar spectrum) limits further commercialization. Here we would like to introduce our recent study on visible and near-IR light responsible photocatalysts composited with 2D nanomaterials.[1-3] 1) Black phosphorous (BP) sensitized Au/ LTO nanostructures for plasmon enhanced photocatalytic hydrogen production with visible and near-infrared light. Using BP sensitized Au/ LTO (BP-Au/LTO), a broadband solar response photocatalyst was first time designed and used as efficient photocatalyst for H2 production. The optimum H2 production rates of BP-Au/LTO were ca. 0.74 and 0.30 mmol g-1 h-1 under >420 nm and >780 nm light irradiation, respectively. Broad absorption of BP and plasmonic Au contribute to the enhanced photocatalytic activity in the visible and NIR regions. Time-resolved diffuse reflectance spectroscopy revealed effcient interfacial electron transfer from excited BP and Au to LTO in accordance with the high photoactivities. 2) Graphitic-C3N4 (g-C3N4) hybridized N-doped LTO (NLTO) 2D layered composites for efficient visible-light-driven photocatalyst. Perovskite-type LTO, having a layered structure and the separated H2 and O2 evolution sites, is attractive as an efficient photocatalyst. However, the photocatalytic activity is often limited by the poor electron mobility and no visible light absorption. Here, 2D layered composite hybridized by 2 nm thick g-C3N4 and 7 nm thick NLTO nanosheets was developed to exhibit high photocatalytic activities for H2 production via water splitting and dye degradation under the UV and visible light irradiation, due to the interfacial charge transfer at the interface between g-C3N4 and NLTO. Keywords: photocatalyst • visible light • near infrared light • 2D nanomaterials [1] [2] [3]

M. Zhu, X. Cai, M. Fujitsuka, J. Zhang, and T. Majima, Angew. Chem. Int. Ed. 2017, on the web. X. Cai, J. Zhang, M. Fujitsuka, and T. Majima, Appl. Catal. B Environ. 2017, 202, 191-198. Z. Lou, M. Fujitsuka, and T. Majima, J. Phys. Chem. Lett., 2017, on the web.

23

Wuhan, China

Plenary Lecture PL3

Photocatalytic water splitting and CO2 reduction using metal oxide, sulfide materials, and reduced graphene oxide Akihiko Kudo Department of Applied Chemistry, Tokyo University of Science, Tokyo, Japan [email protected]

Abstract: Water splitting and CO2 fixation of uphill reactions can be regarded as artificial photosynthesis, because light energy is converted to chemical energy [1]. In the present paper, we introduce various metal oxide and sulfide photocatalysts and photoelectrochemical cells aiming at artificial photosynthesis. Rh and Sb-codoped SrTiO3 photocatalyst loaded with an IrO2 cocatalyst is active for water splitting into H2 and O2 under visible light and simulated sunlight irradiations as a single particle type of photocatalyst [2]. This photocatalyst responds to 500 nm. SrTiO 3:Rh of a H2-evolving photocatalyst and BiVO4 of an O2-evolving photocatalyst construct various types of Z-schematic photocatalyst systems with Fe3+/Fe2+, [Co(bpy)3]3+/2+, [Co(phen)3]3+/2+, and a conductive reduced graphene oxide (RGO) of electron mediators and even without an electron mediator [3-5]. It is noteworthy that a photocatalyst sheet consisting of SrTiO 3:Rh,La and BiVO4:Mo powders with Au and carbon contacting layers shows a quite high activity [6,7]. Metal sulfide photocatalysts that are normally unstable for water splitting into H 2 and O2 in the absence of an electron donor can be employed for Z-schematic photocatalyst systems for water splitting. Z-schematic photocatalyst systems composed of metal sulfides of H 2-evolving photocatalysts with TiO2 and BiVO4 of O2-evolving photocatalysts with RGO and Co complexes of electron mediators show activity for water splitting into H 2 and O2 [8-10]. These photocatalyst materials can also be employed for photoelectrochemical system for solar water splitting [9,11]. Ag/BaLa4Ti4O15 and Ag/KCaSrTa5O15 photocatalysts with wide bandgaps show activities for CO2 reduction to form CO and HCOOH in an aqueous medium without any sacrificial reagents [1214]. O2 evolved with a stoichiometric amount under UV irradiation indicating that water reacts as an electron donor. Thus, an uphill reaction of CO2 reduction accompanied with water oxidation was successfully achieved. CuGaS2-RGO/BiVO4 of a Z-scheme photocatalyst system is active for water splitting and CO2 reduction to CO under visible light irradiation without any sacrificial reagents [10]. This is the first time to demonstrate CO2 reduction using water as an electron donor in a powdered photocatalyst system with visible light response. Keywords: Photocatalyst • water splitting • CO2 reduction • reduced graphene oxide [1] A. Kudo, Y. Miseki, Chem. Soc. Rev., 2009, 38, 253. [2] R. Asai, H. Nemoto, Q. Jia, K. Saito, A. Iwase, A. Kudo, Chem. Commun. 2014, 50, 2543. [3] Y. Sasaki, H. Kato, A. Kudo, J. Am. Chem. Soc., 2013, 135, 5441. [4] H. Kato, Y. Sasaki, N. Shirakura, A, Kudo, J. Mater. Chem. A, 2013, 1, 12327. [5] A. Iwase, Y. H. Ng, Y. Ishiguro, A. Kudo, R. Amal, J. Am. Chem. Soc., 2011, 133, 11054. [6] Q. Wang, T. Hisatomi, Y. Suzuki, Z. Pan, J. Seo, M. Katayama, T. Minegishi, H. Nishiyama, T. Takata, K. Seki, A. Kudo, T. Yamada, K. Domen, J. Am. Chem. Soc., in press. [7] Q. Wang, T. Hisatomi, Q. Jia, H. Tokudome, M. Zhong, C. Wang, Z. Pan, T. Takata, M. Nakabayashi, N. Shibata, Y. Li, I. Sharp, A. Kudo, T. Yamada, K. Domen, Nature Mater., 2016, 15, 611. [8] K. Iwashina, A. Iwase, Y. Hau Ng, R. Amal, A. Kudo, J. Am. Chem. Soc., 2015, 137, 604. [9] T. Kato, Y. Hakari, S. Ikeda, Q. Jia, A. Iwase, A. Kudo, J. Phys. Chem. Lett., 2015, 6, 1042. [10] A. Iwase, S. Yoshino, T. Takayama, Y. H. Ng, R. Amal, A. Kudo, J. Am. Chem. Soc., 2016, 138, 10260. [11] Q. Jia, K. Iwashina, A. Kudo, Proc. Natl. Acad. Sci. USA, 2012, 109, 11564. [12] K. Iizuka, T. Wato, Y. Miseki, K. Saito, A. Kudo, J. Am. Chem. Soc., 2011, 133, 20863. [13] T. Takayama, A. Iwase, and A. Kudo, Bull. Chem. Soc. Jpn., 2015, 88, 538. [14] H. Nakanishi, K. Iizuka, T. Takayama, A. Iwase, A. Kudo, ChemSusChem, 2017, 10, 112.

24

Wuhan, China

Plenary Lecture PL4

Tailoring Morphology and Porosity of Graphene- and Carbon Nitride-Based Nanostructures Mietek Jaroniec* Department of Chemistry and Biochemistry, Kent State University, Kent, Ohio 44242 USA * Corresponding author: [email protected]; 1-330-672 3790

Abstract: Since 2000 a substantial progress has been made in the development of two-dimensional (2D) nanomaterials. Although these materials possess many exceptional features, their main drawback is tendency to re-stacking into low surface area aggregates. Therefore, extensive studies have been carried out toward assembly of 2D nanosheets into 3D structures. Namely, the ongoing research efforts in this area are focused on the development of 3D architectures with controlled morphology and porosity suitable for specific adsorption, catalytic and photocatalytic processes that are essential for environmental and energy-related applications. Among numerous 2D nanomaterials, graphene and graphitic carbon nitride (g-C3N4) attracted a lot of attention because graphene features an exceptional electron mobility, while g-C3N4 is one of the most important metal-free photocatalysts. Therefore, these 2D nanomaterials are often coupled and combined with other photocatalytic and/or conductive nanomaterials to introduce or enhance their photocatalytic performance (e.g., [1,2]). The aforementioned coupling of graphene and g-C3N4 with various inorganic photocatalytic nanoparticles or nanosheets is often used not only to introduce or enhance photocatalytic activity but also to increase the specific surface area and porosity. While extensive literature is available on the design and synthesis of various composite photocatalysts consisting of 2D nanosheets of graphene and g-C3N4 with various inorganic photocatalytic nanoparticles, much less has been done toward development of these composites with tunable surface area, porosity and morphology – features that are very essential for many photocatalytic applications. In the case of 3D architectures consisting of 2D nanosheets and inorganic nanoparticles porosity can be easily created by assembly of exfoliated graphene and/or gC3N4 in the presence of nanoparticles, which provide desired photocatalytic properties and act as pillars to prevent re-staking of nanosheets and create porosity. To increase porosity of these composite architectures holey graphene and g-C3N4 nanosheets can be used. Another way of creating 3D architectures with well-defined and/or hierarchical porosity is the use of suitable nanostructured hard templates. Hard templating is also effectively used for achieving various morphologies such as monoliths, films and spherical particles ranging from hollow spheres to yolkshell, core-shell, and multi-shell structures [3]. Although less explored, soft templating-type assembly of graphene and g-C3N4 nanosheets can also be used for controlling morphology and porosity of 3D composite architectures. Keywords: Graphene • Carbon nitride • Morphology • Porosity • Composite photocatalysts [1] Q.J. Xiang, J.G. Yu, M. Jaroniec. Chem. Soc. Rev. 2012, 41, 782. [2] S.W. Cao, J.X. Low, J.G. Yu, M. Jaroniec. Adv. Mater. 2015, 27, 2150. [3] J. Liu, N.P. Wickramaratne, S.Z. Qiao, M. Jaroniec. Nature Mater. 2015, 14, 763.

25

Wuhan, China

Plenary Lecture PL5

Design of Nanostructured Photocatalysts for Efficient Hydrogen Generation from Carrier Molecules Hiromi Yamashita*, Kohsuke Mori, Yasutaka Kuwahara Address: Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871, Japan e-mail: [email protected]

Abstract: Nanostructured plasmonic nobel metals such as Au and Ag are attractive materials that strongly absorb visible light owing to their localized surface plasmon resonance (LSPR) [1-6]. Up to now, the search for efficient and safe hydrogen storage materials is of crucial significance. Ammonia borane (AB: NH3BH3) and formic acid (FA) with high hydrogen content are attractive chemical hydrogen storage candidates. In this study, we demonstrated that the plasmonic nanostructures, including color-controlled Ag nanoparticles (NPs), novel MoO3-x nanosheets, and core-shell Au@Pd NPs on Metal organic frameworks (MOFs) was used as efficient catalysts under visible light for H2 production from these hydrogen storage molecules. The Ag NPs were prepared on SBA-15 mesoporous silica by microwave-assisted alcohol reduction in the presence or absence of sodium laurate. MoO 3-x nanosheets were prepared by oxidizing metal molybdenum powders with H2O2 followed by the solvothermal treatments in ethanol. The catalytic performances were investigated for dehydrogenation of AB in aqueous suspensions with plasmonic catalysts. The activity for H 2 production was greatly enhanced by the visible light irradiation induced by LSPR specially on the rod type Ag NPs with lager aspect ratio. Plasmonic semiconductors is another novel category with low resistive loss and earth abundance. By a facile nonaqueous access, MoO3-x nanosheets with tunable LSPR from visible light to near infrared were prepared. Under visible light irradiation, such plasmonic MoO3-x nanosheets displayed dramatically enhanced H2 production rate from AB. Furthermore, a synergistic catalysis of plasmonic Au@Pd NPs supported on titanium doped zirconium based amine-functionalized MOF(UiO-66(Zr100-xTix)) was observed for boosting H2 production from FA. The electronically promoted Pd by the charge transfer arising from the difference in work function of Pd and Au metals and the LSPR effect of Au play a crucial role in achieving high catalytic activity for H 2 production from FA.

Figure 1. (A) Plasmonic silver nanoparticles and (B) molybdenum oxide nanosheets for enhanced H 2 evolution from H2 carrier molecules under visible light. Keywords: Photocatalyst • Hydrogen • Plasmonic• Nanoparticle • Nanosheet [1] M. Wen, K. Mori, K, Y. Kuwahara, H. Yamashita, ACS Energy Lett., 2017, 2, 1-7. [2] H. Cheng, Y. Kuwahara, K. Mori, H. Yamashita, et al., J. Am. Chem. Soc., 2016, 138, 9316-9324. [3] M. Wen, K. Mori, Y. Kuwahara, H. Yamashita, ACS Appl. Mat. & Interf., 2016, 8, 21278-21284. [4] P. Verma, K. Mori, Y. Kuwahara, H. Yamashita, J. Mater. Chem. A, 2016, 4, 10142-10150. [5] H. Cheng, T. Kamegawa, K. Mori, H. Yamashita, Angew. Chem. Int. Ed., 2014, 53, 2910-2914. [6] K. Fuku, T. Kamegawa, K. Mori, H. Yamashita, Angew. Chem. Int. Ed., 2013, 52, 7446-745.

26

Wuhan, China

Plenary Lecture PL6

PEC-PV tandem cell for photoelectrochemical water splitting for solar hydrogen production Jae Sung Lee* School of Energy and Chemical Engineering, Ulsan National Institute of Science & Technology (UNIST), Ulsan, Korea e-mail: [email protected]

Abstract: About 400 semiconductor solids are known to have photocatalytic activity for water splitting. Yet there is no single material that could satisfy all the requirements for desired photocatalysts: i) suitable band gap energy (1.7 eV< Eg < 2.3 eV) for high efficiency, ii) proper band position for reduction and/or oxidation of water, iii) long-term stability in aqueous solutions, iv) low cost, v) high crystallinity, and vi) high conductivity. Hence, in the selection of photocatalytic materials, we better start from intrinsically stable materials made of earth-abundant elements. The band bap energy is also the primary consideration to absorb ample amount of solar energy of wide wavelength spectrum. It sets the limit of theoretically maximum efficiency and it could also be extended by band engineering techniques. Upon selection of the candidate materials, we can also modify the materials for full utilization their potentials. The main path of efficiency loss in PEC water splitting process is recombination of photoelectrons and holes. We discuss the material designs including i) p-n heterojunction photoanodes for effective electron-hole separation, ii) electron highway to facilitate interparticle electron transfer, iii) metal or anion doping to improve conductivity of the semiconductor and to extend the range of light absorption, iv) one-dimensional nanomaterials to secure a short hole diffusion distance and vectoral electron transfer, and v) loading co-catalysts for facile charge separation. Finally, we need to construct a stand-alone solar fuel production system by combining with a solar cell in tandem, which provides bias voltage needed for the photolytic reactions making possible the fuel production only with solar energy without any external energy supply. b

a

Light

Phaeophyceae

Chlorophyta

Rhodophyta

Figure. Wavelength-selective solar light absorption by hetero-type dual photoanode (HDP) vs. natural seaweeds. (a) HDP made with different band gap materials (e.g., BiVO4 and Fe2O3). (b) Distribution of seaweeds, chlorophyta (green algae), phaeophyceae (brown algae) and rhodophyta (red algae) with depth of sea that absorb different parts of solar spectrum. Keywords: solar hydrogen • photoelectrochemical water splitting • charge separation • nanostructures • stand-alone system [1] [2] [3]. [4] [5]

J. H. Kim, J.-W. Jang, Y.H. Jo, F.F. Abdi, Y.H. Lee, R. van de Krol, J.S. Lee, Nat. Commun. 2016, 7, 13380 J.Y. Kim, D.H. Youn, K. Kang, and J.S. Lee, Angew. Chem. Int. Ed. 2016, 128, 11012 – 11016 Y.J. Jang, I. Jeong, J. Lee, J. Lee, M.J. Ko and J.S. Lee, ACS Nano. 2016, 10(7) 6980-6987 J.H. Kim, Y. Jo, J.W. Jang, H.J. Kang, Y.H. Lee, D.S. Kim, Y. Jun, and J.S. Lee, ACS Nano. 2015, 9(12), 11820–11829 . Y.J. Jang, J.W. Jang, J. Lee, J.H. Kim, S. Cho, H. Kumagai, T. Minegishi, J. Kubota, K. Domen, and J.S. Lee, Energy Env. Sci. 2015, 8, 3597-3604.

27

Wuhan, China

Keynote Lectures

28

Wuhan, China

29

Wuhan, China

Keynote Lecture KL1

Semiconductor Materials for Bifunctional Photoelectrochemical Energy Conversion ** Lianzhou Wang* Nanomaterials Centre, School of Chemical Engineering and AIBN, the University of Queensland, St Lucia, QLD, Australia, *E-mail: [email protected]

Abstract: The capability to design functional nanomaterials with desirable structures and properties remains an important challenge to R&D sectors. Our research motivation is to design highly efficient semiconductor based photoelectrochemical systems that can convert abundant solar energy into valuable solar fuels such as hydrogen and/or electricity. In this talk, we give a brief overview on our recent progresses in designing semiconductor metal oxide materials for photoelectrochemical energy conversion. In more details, we have been focusing the following three aspects; 1) self-assembly of two-dimensional oxide nanosheet materials as innovative photoelectrodes for switchable photocurrent generation, 2) new types of bifunctional photoelectrochemical reactor design which can simultaneously not only generate solar fuels but also decompose toxic/pollutants from the reactors; and 3) new photoelectodes for improved conversion efficiency in dye-sensitized solar cells, solar battery and new generation perovskite solar cells.

Keywords: semiconductor photocatalysis, 2D nanosheets, photoeclectrochemical energy conversion, solar fuels, solar electricity

[1] [2] [3] [4]

Wang, LZ, Sasaki, T., Chem. Rev. 2014, 114 (19), pp 9455–9486. Zong, X, Li, C, Wang LZ et al, Angew. Chem. 2014, 4399. Wang, Q., Wang LZ, et al, Adv. Energy Mater, 2015, doi:10.1002/aenm.201501418. Peerakiatkhajohn, P, Wang LZ., et al, Adv. Mater., 2016, doi:10.1002/adma.201601525.

30

Wuhan, China

Keynote Lecture KL2

Composite g-C3N4 Nanostructures for Efficient Photocatalytic Hydrogen Evolution Bin Liu* Address: School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, Singapore 637459 e-mail: [email protected]

Abstract: Hollow one-dimensional (1-D) nanostructures have drawn great attention in heterogeneous photocatalysis. Herein, we report that tapered polyacrylonitrile-derived carbon (CPAN)/g-C3N4 composite nanotubes can be synthesized through a facile sulfur-mediated selftemplating method via thermal condensation of polyacrylonitrile (PAN), melamine and sulfur. The hollow tapered C-PAN/g-C3N4 composite nanotubes exhibit exceptional photocatalytic H2 evolution performance under visible light irradiation. The 5 wt% C-PAN/g-C3N4 composite nanotubes show 16.7 times higher photocatalytic H2 evolution rate than that of pure g-C3N4, which is even 4.7 times higher than that of 5 wt% C-PAN/g-C3N4 nanosheet composite obtained without sulfur. The hollow nanotubular composite structure provides g-C3N4 with higher specific surface area, enhanced light absorption and better charge carrier separation and transfer, which synergistically contribute to the superior photocatalytic activity. Our work provides a new strategy to develop carbon-based architected photocatalysts with outstanding photocatalytic activity.

Keywords: carbon nitride • photocatalysis • hydrogen • composite • nanotube

31

Wuhan, China

Keynote Lecture KL3

Layered Bismuth Oxyhalide Photocatalysts ** Lizhi Zhang* Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Environmental & Applied Chemistry, College of Chemistry, Central China Normal University, Wuhan 430079, P. R. China e-mail: [email protected]

Abstract: In recent years layered bismuth oxyhalide nanomaterials have received more and more concerns as promising photocatalysts because their unique layered structures endow them with fascinating physicochemical properties and thus great potential photocatalytic applications for environment remediation and energy harvesting. In this talk, I will first discuss the facet-dependent photoactivity and molecular oxygen activation pathways of bismuth oxyhalides, and then report their layered structure related internal electric field tuning strategies, and finally highlight some oxygen vacancy effects of bismuth oxyhalides, including oxygen vacancy mediated nitrogen activation under visible light, as well as oxygen vacancy mediated Bi12O17Cl2/MoS2 Janus bilayer junctions formation and their superior visible light hydrogen evolution via atomic level charge flow steering.

Keywords: Layered bismuth Oxyhalide • Janus photocatalyst • Molecular oxygen activation • Nitrogen activation • Hydrogen evolution [1] [2] [3] [4] [5] [6]

Li, J.; Li, H.; Zhan, G. M. Zhang, L. Z. Solar Water Splitting and Nitrogen Fixation with Layered Bismuth Oxyhalides. Acc. Chem. Res. 2017, 50, 112-121. Li, J.; Cai, L. J.; Shang, J.; Yu, Y.; Zhang, L. Z. Giant Enhancement of Internal Electric Field Boosting Bulk Charge Separation for Photocatalysis. Adv. Mater. 2016, 28, 4059-4064. Li, J.; Zhan, G. M.; Yu, Y.; Zhang, L. Z. Superior Visible Light Hydrogen Evolution of Janus Bilayer Junctions via Atomic Level Charge Flow Steering. Nat. Commun. 2016, 7, 11480-11488. Li, H.; Shang, J.; Ai, Z. H.; Zhang, L. Z. Efficient Visible Light Nitrogen Fixation with BiOBr Nanosheets of Oxygen Vacancies on the Exposed {001} Facets. J. Am. Chem. Soc. 2015, 137, 6393−6399. Zhao, K.; Zhang, L. Z.; Wang, J. J.; Li, Q. X.; He, W. W.; Yin, J. J. Surface Structure-Dependent Molecular Oxygen Activation of BiOCl Single-Crystalline Nanosheets. J. Am. Chem. Soc. 2013, 135, 15750−15753. Jiang, J.; Zhao, K.; Xiao, X. Y.; Zhang, L. Z. Synthesis and Facet-Dependent Photoreactivity of BiOCl Single-Crystalline Nanosheets. J. Am. Chem. Soc. 2012, 134, 4473−4476.

32

Wuhan, China

Keynote Lecture KL4

Organic inorganic perovskites photocatalysis: dynamic equilibrium of methylammonium lead iodide in aqueous solution for hydrogen evolution Sunghak Park, Woo Je Chang, and Ki Tae Nam* Department of Materials Science and Engineering, Seoul National University, Seoul, 08826, Korea Tel: +82-2-880-8305, e-mail: [email protected]

Abstract: The solar-driven splitting of hydrohalic acids (HX) represents one of the most important

and fastest growing research directions for future H2 production. Hydrogen iodide (HI) splitting for H2 production has been extensively investigated, especially in thermochemical water splitting processes. When iodine and sulfur participate in this process in the forms of hydrogen iodide and sulfuric acid, hydrogen from the water splitting can be continuously generated with high efficiency in a large-scale closed system, which is known as the iodine-sulfur cycle. Because of the thermodynamic requirement for high temperatures, centralized production systems coupled with nuclear power have been explored the most. In addition to the merits that are applicable to the iodine-sulfur water splitting cycle, solar-driven HX splitting represents an important alternative process to water splitting. Compared to water splitting involving four electrons, a lower overpotential is required because only two electrons are involved. As a result, the overpotential is almost zero in the case of iodide ion oxidation. In addition to the hydrogen, the resulting chemicals (X2/X3-) can be used to propagate the continuous process in a closed cycle and are themselves useful products that, add value. In an effort to develop a cost-effective and easily scalable process, we suggest a new strategy for photocatalytic HI splitting using methylammonium lead iodide (MAPbI 3). Considering the fact that MAPbI3 is a water-soluble ionic crystal, we pay attention to the dynamic equilibrium of the precipitation and dissolution of the ionic crystal in saturated solutions. MAPbI 3 powder was stably existing in aqueous HI solution by the principle of dynamic equilibrium. The I - and H+ concentrations of the aqueous solution were determined to be the critical parameters for the stabilization of the tetragonal MAPbI 3 phase. Stable and efficient H2 production under visible light irradiation was demonstrated.

Keywords: Organic inorganic perovskites • Methylammonium lead iodide • Photocatalysis • Dynamic equilibrium • Hydrogen iodide (HI) splitting [1]

Sunghak Park et al., Nature Energy 2, 16185 (2016)

33

Wuhan, China

Keynote Lecture KL5

Photo-reactor design of sunlight harvesting for solar H2 by water splitting Van Huy Nguyen, Duan-Xing Li and Jeffrey Chi-Sheng Wu* Department of Chemical Engineering, National Taiwan University, acronyms acceptable, City, Country e-mail: [email protected]

Abstract: Nowadays, how to solve the lack of sufficient clean and natural energy sources, as well as the environmental concerns has been received much attention. We carry out the research advances made in the design and development of photo-reactor for solar energy conversion to chemical energy by water splitting and carbon dioxide (CO2) reduction. The photocatalytic water splitting and photocatalytic reduction of CO2 using particulate semiconductors are a potentially scalable and economically feasible technology for converting solar energy into hydrogen and hydrocarbons, respectively. We have recently developed a novel twin-reactor system that combines the advantages of both Z-scheme and H-type reactor systems to carry out water-splitting reaction, as shown in Figure 1, which can separate H2 and O2 simultaneously during water splitting [1, 2]. This modified ion-exchange membrane not only allows the transport of protons, but also the exchange of the mediator ions (Fe2+/Fe3+) in solution so that no wire is required like photoelectron system. Further research indicates that effective combining H2 production with wastewater treatment in the twin reactor is a green and promising technology. In this process, organic wastewater has been considered as a feedstock for H2 production as shown in Figure 2. From the thermodynamic viewpoint, the Gibbs free energy of organics oxidation can be applied to reduce the Gibbs free energy of pure water oxidation in the water splitting. Overall, pure H 2 can be obtained, and treated wastewater and CO2 can be discharged separately in the twin-reactor system.

Keywords: Photocatalysis • H2 • Solar energy • CO2 • Twin reactor [1] [2]

Chen-Chia Lo, Chao-Wei Huang, Chi-Hung Liao, Jeffrey C. S. Wu, International Journal of Hydrogen Energy, 35(4), 15231529 (2010) Sheng-Hung Yu, Cheng-Wei Chiu, Yi-Ting Wu, Chi-Hung Liao, Van-Huy Nguyen, Jeffrey C. S. Wu, Applied Catalysis A: General, 518, 158-166 (2016)

34

Wuhan, China

Keynote Lecture KL6

Enhanced water splitting via inhibition of hydrogen-oxygen recombination over graphene photocatalyst under visible light irradiatione Gongxuan Lu Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, China, 730000 e-mail: [email protected]

Abstract: Recently, photocatalytic hydrogen generation from water-semiconductor catalyst

dispersion attracted world-wide attention because the solar energy could be converted directly into hydrogen only in very simple set-up in scale-up scale. Although many photocatalysts were reported to be active for this reaction, the efficiency is still quite low. In this work, we found that hydrogen and oxygen recombination took place rapidly in the photocatalyst dispersion and resulted in very low hydrogen generation rate in pure water. The activation energy of H2 and O2 recombination reaction is 16.5 KJ/mol regardless of light irradiation or not. In this case, the photocatalytic evolved H2 could react rapidly with the evolved O2 to form H2O again, eventually leading to no net H2 and O2 evolution during irradiation. The recombination of hydrogen and oxygen can be inhibited by addition of oxygen transfer reagent hemin chloride (HC). With help of HC, photocatalytic generated oxygen was captured by HC and transferred away from photocatalyst surface, then the backward reaction of hydrogen-oxygen recombination was successfully restrained. The photocatalytic hydrogen evolution amount in graphene photocatalyst dispersion was significantly enhanced under this condition. The isotopes analysis results confirmed that both the H2 and O2 were from water. The HC could be recycled by releasing the O2 with Ar gas bubbling. This study clarified the main impediment reason of low efficient photocatalytic hydrogen generation in semiconductor-water dispersion and present available method to avoid this negative reaction. This finding will help to design high active catalytic system for solar energy to hydrogen conversion and open a new window for overall water splitting research. Keywords: photocatalytic hydrogen generation; inhibition of hydrogen and oxygen recombination; oxygen transfer reagent HC; enhancement of hydrogen generation; isotopes analysis

35

Wuhan, China

Keynote Lecture KL7

On the way to efficient graphene-based composite photocatalysts for solar energy conversion** Yi-Jun Xu* Address: State Key Laboratory of Photocatalysis on Energy and Environment, College of Chemistry, Fuzhou University, Fuzhou, P. R. China e-mail: [email protected]

Abstract: Graphene-based composite photocatalysts have attracted tremendous interests over the past few years due to the great promise that graphene holds to construct efficient composite photocatalysts toward solar energy conversion. 1 Thus far, graphene-based composite photocatalysts have been utilized in various photoredox processes, including nonselective degradation of pollutants, selective organic transformation for fine chemicals synthesis, water splitting to clean hydrogen and photoreduction of CO2 to solar fuels.1 Although the hunt is on for applications that can exploit graphene’s remarkable properties, how to make better use of graphene still needs more efforts.1a, 1b Our group has been carrying out a series of studies on graphene-based composite photocatalysts since 2010 and paid much attention to the strategies on how to rationally bring the potential of graphene in efficiently enhancing the photocatalytic performance of composites into better play.2-8 In 2010, we presented a systematic comparison study of the similarity and difference between graphene and its allotrope (e.g., carbon nanotubes) in improving the photoactivity of semiconductor (taking P25 TiO2 as an example).2 Our results manifest that, TiO2-graphene composites obtained via a random “hard” integration of solid TiO2 nanoparticles and graphene oxide are in essence the same as other TiO2-carbon (carbon nanotubes, fullerenes, and activated carbon) counterparts on enhancing the photoactivity of TiO2, although graphene by itself has unique structural and electronic properties. Following this seminar work, 2 we subsequently focus on developing various strategies to synthesize more efficient graphene-based composite photocatalysts by taking better advantage of the structural and electronic properties of graphene, including developing the efficient preparation method to improve the interfacial contact between graphene and semiconductor,3 using a combined strategy of decreasing defects of graphene and improving the interfacial contact between graphene and semiconductor,4 optimizing the atomic charge carrier transfer pathway across the interface between graphene and semiconductor, 5 independently investigating the geometry effect of three-dimensional graphene with significantly deteriorated electrical conductivity on the photocatalytic performance of graphene-semiconductor composites,6 systematically studying the photosensitizer role of graphene and how to boost its photosensitive efficiency,7 constructing metal-free, robust, and regenerable three-dimensional graphene-organics aerogel with high and stable photosensitization efficiency. 8 Based on these progresses, joint experimental and theoretical efforts are expected to take us further along the way to advancing efficient graphene-based composite photocatalysts for solar energy conversion. Keywords: graphene • semiconductor • photocatalysis • solar energy conversion [1] a) N. Zhang, M.-Q. Yang, S. Liu, Y. Sun, Y.-J. Xu, Chem. Rev., 2015, 6, 10307-10377; b) M.-Q. Yang, N. Zhang, M. Pagliaro, Y.-J. Xu, Chem. Soc. Rev., 2014, 43, 8240-8254; c) N. Zhang, Y.-J. Xu, CrystEngComm, 2016, 18, 24-37; d) Q. Xiang, J. Yu, M. Jaroniec, Chem. Soc. Rev., 2012, 41, 782-796. [2] Y. Zhang, Z.-R. Tang, X. Fu, Y.-J. Xu, ACS Nano, 2010, 4, 7303-7314. [3] Y. Zhang, Z.-R. Tang, X. Fu, Y.-J. Xu, ACS Nano, 2011, 5, 7426-7435. [4] Y. Zhang, N. Zhang, Z.-R. Tang, Y.-J. Xu, Phys. Chem. Chem. Phys., 2012, 14, 9167-9175. [5] N. Zhang, M.-Q. Yang, Z.-R. Tang, Y.-J. Xu, ACS Nano, 2014, 8, 623-633. [6] B. Weng, Y.-J. Xu, ACS Appl. Mater. Interfaces, 2015, 7, 27948-27958. [7] a) Y. Zhang, N. Zhang, Z.-R. Tang, Y.-J. Xu, ACS Nano, 2012, 6, 9777-9789; b) M.-Q. Yang, Y.-J. Xu, J. Phys. Chem. C, 2013, 117, 21724-21734; c) K.-Q. Lu, N. Zhang, C. Han, F. Li, Z. Chen, Y.-J. Xu, J. Phys. Chem. C, 2016, 120, 27091-27103. [8] M.-Q. Yang, N. Zhang, Y. Wang, Y.-J. Xu. J. Catal., 2017, 346, 21-29.

36

Wuhan, China

Keynote Lecture KL8

Alkaline Earth Modified g-C3N4 Nanocomposites for NOx Removal Ilias Papailias, Tatiana Giannakopoulou, Nadia Todorova, Sofia Karapati, Christos Trapalis* Institute of Nanoscience and Nanotechnology, NCSR “Demokritos”, Agia Paraskevi, Attikis, 15341, Greece *[email protected]

Introduction: Atmospheric pollution caused by the presence of nitrogen oxides (NOx) in the air, has been recognized as one of the most serious environmental problems [1]. Therefore, the development of efficient methods to promote the NOx removal from the atmosphere is becoming increasingly important. At present, g-C3N4 has been successfully used as an efficient photocatalyst for NO oxidation [2]. However, there has been little progress in eliminating the released NO 2. In this work, novel alkaline earth modified g-C3N4 photocatalysts were prepared and tested for efficient NOx removal. Experimental Section: The modified g-C3N4 photocatalysts were synthesized by mixing melamine with specific amounts of the appropriate alkaline earth acetates (0, 5 and 10 wt%) and annealing at 550 oC for 3h under Ar flow. More specifically, magnesium, calcium and barium acetate were used as alkaline earth precursors and the samples were named MgX, CaX and BaX (where X is the wt%). The prepared materials were then tested for NO oxidation and the total NOx removal efficiency was measured. Furthermore, photocatalytic measurements under NO2 flow were performed and the behavior of the materials was evaluated. Results: The photocatalytic measurements showed that the alkaline earth modified g-C3N4 nanocomposites significantly inhibit NO 2 emissions. This can be attributed to the basic character of the nanocomposites, facilitating an “adsorb and shuttle” approach. Most notably, in the case of Ba10 the decrease reached 65%. The NO oxidation ability of the nanocomposites was inferior to pure g-C3N4, because of the lesser amount of photocatalyst present, but due to the extremely low NO2 emissions the total NO x efficiency was considerably superior. Measurements under NO2 flow revealed that even without irradiation the modified nanocomposites adsorb high amounts of NO2 (Fig. 1), confirming the important contribution of alkaline earths [3]. Conclusions: Novel alkaline earth modified g-C3N4 photocatalysts were synthesized. The presence of alkaline earth significantly reduces the amount of NO2 released during the NO oxidation process. As a result, the total NOx efficiency is greatly enhanced and the overall air quality is improved. Keywords: photocatalysis • g-C3N4 • alkaline earth • NO oxidation • NO2 elimination [1] [2] [3]

S.D. Beevers, E. Westmoreland, M.C. de Jong, M.L. Williams, D.C. Carslaw, Atmos. Environ., 2012, 54, 107-116 W.J. Ong, L.L. Tan, Y.H. Ng, S.T. Yong, S.P. Chai, Chem. Rev., 2016, 116, 7159-7329 M. Pérez-Nicolás, J. Balbuena, M. Cruz-Yusta, L. Sánchez, I.Navarro-Blasco, J.M. Fernández, J.I. Alvarez, Cem. Concr. Res., 2015, 70, 67-76.

37

Wuhan, China

Keynote Lecture KL9

Controlling compositions and microstructures of carbon nitride for high photocatalytic activity** Gang Liu* Address: Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016, China e-mail: [email protected]

Abstract: Graphitic carbon nitride has emerged as a promising metal-free photocatalyst for solar energy conversion. Despite many merits including easy-availability, good stability, visible light responsive and environmentally friendly, its application is largely hindered by the high bulk recombination probability of photogenerated charge carriers and narrow visible light responsive range only to around 470 nm. To improve solar energy conversion efficiency, tailoring its microstructure at the atomic level is highly necessary. Graphitic carbon has a unique atomic structure with the coexistence of covalent bonds, hydrogen bonds and van der Waals forces, making it versatile to tailor its microstructure by controlling bonding structure. In this talk, the recent progress in forming amorphous graphitic carbon nitride by destroying weak hydrogen bonds and van der Waals forces will be introduced. It was found that amorphization can greatly narrow the bandgap of carbon nitride from 2.82 eV to 1.90 eV due to the formation of abundant band tails close to conduction and valence bands. Moreover, the radiative recombination in the amorphous carbon nitride is completely quenched. As a consequence, the photocatalytic hydrogen generation of carbon nitride is improved by one order of magnitude. Further study shows that selective destroying hydrogen bonds leads to the maximized photocatalytic hydrogen evolution. These results demonstrate the great potential of tailoring bonding structure of graphitic carbon nitride in improving photocatalytic activity. Keywords: carbon nitride• photocatalysis [1] [2] [3] [4] [5] [6] [7] [8]

X. C. Wang, K. Maeda, A. Thomas, K. Takanabe, G. Xin, J. M. Carlsson, K. Domen, M. Antonietti, Nat. Mater. 2009, 8, 76. Y. Y. Kang, Y. Q. Yang, L. C. Yin, X. D. Kang, L. Z. Wang, G. Liu, H. M. Cheng, Adv. Mater. 2016, 28, 6471. Y. Y. Kang, Y. Q. Yang, L. C. Yin, G. Liu, H. M. Cheng, Adv. Mater. 2015, 27, 4572. P. Niu, L. C. Yin, Y. Q. Yang, G. Liu, H. M. Cheng, Adv. Mater. 2014, 26, 8046. P. Niu, Y. Q. Yang, J. C. Yu, G. Liu, H. M. Cheng, Chem. Commun., 2014, 50, 10837. P. Niu, L. L. Zhang, G. Liu, H. M. Cheng, Adv. Funct. Mater. 2012, 22, 4763. P. Niu, G. Liu, H. M. Cheng, J. Phys. Chem. C 2012, 116, 11013. G. Liu, P. Niu, C. H. Sun, S. C. Smith, Z. G. Chen, G. Q. Lu, H. M. Cheng, J. Am. Chem. Soc. 2010, 132, 11642.

38

Wuhan, China

Keynote Lecture KL10

Alkali-assisted synthesis of nitrogen deficient graphitic carbon nitride with tunable band structures for efficient visible light-driven hydrogen evolution ** Huijun Yu, Run Shi and Tierui Zhang* Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, China e-mail: [email protected]

Abstract: Based on our previous works[1-6], in this work, we describe a novel one step KOH-assisted route to prepare nitrogen defective g-C3Nx[7], wherein two types of nitrogen defects were selectively introduced in situ during the thermal-polymerization of urea or other nitrogen-rich precursors (such as melamine and thiourea). The introduction of nitrogen defects red-shifted the g-C3Nx absorption edge, with the size of the shift being dependent on the amount of nitrogen defects which can be easily tuned by the KOH:urea ratio. Furthermore, similar results can also be achieved using other alkali compounds (such as NaOH and Ba(OH)2), highlighting the versatility of the method. Due to enhanced visible light absorption and improved charge carrier separation, the g-C3Nx products displayed superior photocatalytic hydrogen performance compared to pristine g-C3N4 under visible light. The synthetic strategy introduced here thus represents a simple and effective way of synergistically optimizing the chemical composition, optical response and photocatalytic properties of g-C3N4-based materials.

Figure 1. With the increase of Nitrogen defects the band gap of g-C3Nx can be reduced to values as small as 2.17 eV, compared with 2.68 eV for pristine g-C3N4. Keywords: photocatalysis • nanostructure • solar fuel • CO2 reduction • visible-light response [1] T. R. Zhang et al., Adv. Mater., 2016, 28, 9454-9477 [2] T. R. Zhang et al., Angew. Chem. Int. Ed., 2016, 55, 4215-4219 [3] T. R. Zhang et al., Adv. Energy Mater., 2016, 6, 1501974 [4] T. R. Zhang et al., Adv. Energy Mater., 2016, 6, 1501241 [5] T. R. Zhang et al., Adv. Mater., 2015, 27, 17824-7831 [6] T. R. Zhang et al., Adv. Mater., 2014, 26, 5613-5618 [7] T. R. Zhang et al., Adv. Mater., 2017, DOI: 10.1002/adma.201605148

39

Wuhan, China

Keynote Lecture KL11

Do we know how to design a photocatalyst for CO 2 reduction? Wojciech Macyk,* Joanna Kuncewicz, Marcin Kobielusz, Tomasz Baran, Szymon Wojtyła Faculty of Chemistry, Jagiellonian University, ul. Ingardena 3, 30-060 Kraków, Poland e-mail: [email protected]

Abstract: The photocatalytic carbon dioxide reduction is a challenging process in which, similarly to photosynthesis, light can be converted to a chemical energy. The energetics of this reaction is very different from the most commonly studied photocatalytic reactions in which pollutants are photooxidized to CO2. Although these two processes are, in principle, opposite to each other, usually the same photocatalysts (mainly oxides, including TiO 2) are considered in both cases. Most of metal oxides, being n-type semiconductors, upon excitation offer strong oxidation properties, but at the same time they are relatively mild reductants. We propose another approach to a photocatalytic CO2 reduction, involving application of p-type semiconductors, offering, in comparison to n-semiconductors, better reduction and worse oxidation properties. As an example, the photocatalytic activity of p-CuI towards carbon dioxide photoreduction (mainly to CO and HCOOH) can be compared to that of TiO2 (P-25).1 The applicability of p-type semiconductors, including g-C3N4, for carbon dioxide valorization will be discussed. 1,2 Other important parameters influencing the photocatalytic CO2 reduction process encompass: redox properties of the material, adsorption of reactants, number of electrons participating in the reduction reaction, the oxidation counterpart of the reaction, and several others. Redox properties of the photocatalysts can be easily determined using spectroelectrochemical methods developed recently in our laboratories.3 Recognition of density of electronic states appears fundamental in understanding and predicting applicability of a photocatalyst for carbon dioxide reduction. The number of electrons participating in reduction reactions should also be taken into account. Methane formation requires eight electrons in total, 4 but carboxylic acids can be synthesized in the process of CO2•– (one-electron reduction of CO2) and R• radicals (one-hole oxidation of RH) coupling.5,6 Do we know how to design a photocatalyst for CO2 reduction? Can layered materials appear good candidates for CO2 reduction photocatalysts? These questions will be analyzed in detail during the presentation. Acknowledgements: The work was supported by the National Science Center (Poland) within the 2015/19/B/ST5/00950 project. Keywords: photocatalytic CO2 reduction • redox properties of semiconductors • g-C3N4 • n-type semiconductors • p-type semiconductors [1] [2] [3] [4] [5] [6]

T. Baran, S. Wojtyła, A. Dibenedetto, M. Aresta, W. Macyk, ChemSusChem 2016, 9, 2933-2938. S. Ye, R. Wanga, M.-Z. Wu, Y.-P. Yuan, Appl. Surf. Sci. 2015, 358, 15–27. E. Świętek, K. Pilarczyk, J. Derdzińska, K. Szaciłowski, W. Macyk, Phys. Chem. Chem. Phys. 2013, 15, 14256-14261. T. Baran, S. Wojtyła, A. Dibenedetto, M. Aresta, W. Macyk, Appl. Catal. B: Environ. 2015, 178, 170-176. T. Baran, A. Dibenedetto, M. Aresta, K. Kruczała, W. Macyk, ChemPlusChem 2014, 79, 708-715. M. Aresta, A. Dibenedetto, T. Baran, S. Wojtyła, W. Macyk, Faraday Discuss. 2015, 183, 413-427.

40

Wuhan, China

Keynote Lecture KL12

Two-dimensional (2D) based photocatalysts for antimicrobial applications Xiangkang Zeng, Gen Wang, Zheng Xin, and Xiwang Zhang* Department of Chemical Engineering, Monash University, Clayton, VIC 3806, Australia e-mail: [email protected] (Xiwang Zhang)

Abstract: Microbial contamination in impaired water has always threatened the health of human beings. Millions of people die from diseases caused by waterborne pathogens every year. Therefore, efficient methods to control or prevent the spread of pathogenic microorganisms in water are urgently needed [1]. Although conventional technologies for water disinfection have been widely used to inactivate pathogens aiming to supply safe drinking water, such as chlorination, ozonation and ultraviolet (UV) irradiation, they are either chemically intensive forming carcinogenic disinfection by-products (DBPs) or energy intensive contributing to the global warming. An important trend to develop alternative disinfection methods is to explore novel approaches which can affordably and robustly inactivate traditional and emerging pathogens, and meanwhile do not create new issues.[5] Recently, as an advanced “green” oxidation technology, photocatalytic water disinfection has attracted increasing attentions. With solar light, the most abundant free renewable energy on the earth, moderate reactive oxygen species (ROS) generated from photoactivated semiconductors can effectively kill pathogens. Therefore, photocatalysis represents an environmentfriendly, cost-effective and efficient advanced oxidation process for water disinfection. Since the discovery of graphene, a typical two-dimensional (2D) materials, many other 2D materials have been successfully synthesised via either top-down exfoliation or bottom-up molecular assembling methods. Due to the unique physicochemical properties along electronic and geometric structures, two-dimensional (2D) nanomaterials are ideal building blocks in the design of novel photocatalysts for various applications including water disinfection. For instance, reduced graphene oxide (rGO) nanosheet is excellent conductive substrate to support nanosized semiconductors in binary and ternary photocatalysts, leading to the spatial isolation of electron-hole pairs [2]. Some 2D semiconductors (Titanium oxide and Tungstate oxide) showed unexpected electron storage capacity, resulting to “memory” photocatalytic activity in pathogen inactivation [3, 4]. In addition, compared to nanoparticles, 2D materials are easy to be immobilised on conventional substrates (glass) or separated from slurry systems [5]. In short, 2D based photocatalysts have great potentials in for antimicrobial applications. Keywords: Two-dimensional (2D) Materials • Photocatalysts • antimicrobial • memory photocatalytic activity [1] X. Zeng, D. McCarthy, A. Deletic, X. Zhang, Advanced Functional Materials, 2015, 25, 4344-4351. [2] X. Zeng, Z. Wang, N. Meng, D. McCarthy, A. Deletic, J, Pan, X. Zhang, Applied Catalysis B: environmental, 2017, 202, 33-41. [3] Z. Xing, X. Zeng, D. McCathy, A. Deletic, G. Wang, X. Zhang, Chemical Communications, 2016, 52, 6985-6988. [4] G. Wang, X. Zeng, Z. Wang, C. Feng, D. McCathy, A. Deletic, X. Zhang, Nanoscale, 2016, 8, 18808 - 18809. [5] G. Wang, X. Zeng, Z. Wang, C. Feng, D. McCathy, A. Deletic, X. Zhang, Water Research, 2016, 94, 363-370.

41

Wuhan, China

Invited Lectures

42

Wuhan, China

43

Wuhan, China

Invited Lecture IL1

Metal Sulfide Nanostructured Materials: An Effective Visible Light Active Photocatalyst for the Degradation of Toxic Organic Pollutants Rengaraj Selvaraj* Department of Chemistry, College of Science, Sultan Qaboos University, P.C. 123, Al-Khoudh, Muscat, Sultanate of Oman e-mail: [email protected]; [email protected]

Abstract: Research into water purification using advanced oxidation technologies are expanding steadily. During the past three decades, it has been shown that advanced oxidation processes (AOPs) are promising technologies for the degradation of recalcitrant, refractory, dangerous, and poisonous organic materials in various wastewaters. Most of these substances are persistent and have been shown to accumulate in the environment. Adverse effects on the human nervous system have been recently reported and have been linked to many health disorders. Therefore, it is important to find innovative and cost effective methods for the safe and complete destruction of toxic organic pollutant. AOPs are effective methods that are capable of transforming almost all organic pollutants into harmless materials such as water and carbon dioxide. The degradation of organic materials by AOPs is based on the production of highly powerful, reactive, and oxidizing hydroxyl radicals. Recently our research group developed series of visible light active metal sulfide photocatalyst such as In2S3, CdS, MnS, HgS, SnS2, ZnxCd1-XS by adopting various synthetic techniques such as solution phase, hydrothermal, solvothermal and microwave assisted method for water and wastewater treatment [1-7]. We demonstrate that several process parameters such as the reaction time and precursor ratio strongly influence the morphology of the final product. The synthesized products have been characterized by a variety of methods, including X-ray powder diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy-dispersive Xray (EDX) analysis, X-ray photoelectron spectroscopy (XPS), and UV-visible diffused reflectance spectroscopy (UV-DRS). Furthermore, the photocatalytic activity studies revealed that the synthesized materials exhibit an excellent photocatalytic performance in rapidly degrading various toxic organics such as organic dyes, volatile organic compounds, pharmaceuticals, pesticides, chlorophenols and EDCs under solar and visible-light irradiation. The improved separation of electrons and holes on the metal sulfide surface allows more efficient channelling of the charge carriers into useful reduction and oxidation reactions rather than recombination reactions. These results suggest that metal sulfide nanostructured materials will be an interesting candidate for photocatalytic detoxification studies under visible light radiation. Further, the development of photocatalytic reactor and application of Green Nanotechnology for the degradation of toxic organics containing wastewater will be discussed during my lecture. Keywords: metal sulfide, photocatalyst, toxic organics, degradation, solar light, visible light. References: [1] [2] [3] [4] [5] [6] [7]

S. Rengaraj, S. Venkataraj, Cheuk-wai Tai, Younghun Kim, Eveliina Repo, Mika Sillanpää, Langmuir, 2011, Vol. 27(9), 5534–5541. S. Rengaraj, S. Venkataraj, S. H. Jee, Y. Kim, C-W.Tai, E. Repo, A. Ferancova, M. Sillanpaa, Langmuir, 2011, Vol. 27(1), 352 - 358. Rengaraj Selvaraj, Kezhen Qi, Salma M. Z. Al-Kindy, Mika Sillanpää, Younghun Kim, Cheuk-wai Tai., RSC Advances., 2014, Vol. 4., pp. 15371 – 15376. Rengaraj Selvaraj, Tharaya Al Fahdi, Bushra Al-Wahaibi, Salma MZ Al-Kindy, Kholood Al-Nofli, Haider Al-Lawati., Reviews on Environmental Health, 2016, Vol. 31., pp. 75-78. Jihong Park, Sungmook Park, Rengaraj Selvaraj, Younghun Kim., RSC Advances., 2015, Vol.5, pp. 52737-52742. Kezhen Qi, Rengaraj Selvaraj, Tharaya Al-Fahdi, Salma Al-Kindy, Younghun Kim, Cheuk-Wai Tai, Mika Sillanpää., MaterialsLetters, 2016, Vol. 166, pp. 116-120. Kezhen Qi, Rengaraj Selvaraj, Tharaya Al Fahdi, Salma Al-Kindy, Younghun Kim, Gui-Chang Wang, Cheuk-Wai Tai, Mika Sillanpää., Applied Surface Science, 2016, Vol. 387., pp. 750-758.

44

Wuhan, China

Invited Lecture IL2

Mechanistics Characteristics of Incorporated Organic Semiconductor with Inorganic (g-C3N4/SrTiO3) for Improved Solar Light Utilisation Kah Hon Leong1, Lan Ching Sim1, Pichiah Saravanan2,3*, Detlef Bahnemann4 1

Department of Environmental Engineering, Faculty of Engineering and Green Technology, Universiti Tunku Abdul Rahman, Jalan Universiti, Bandar Barat, 31900 Kampar, Perak, Malaysia 2 Department of Civil Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia 3 Department of Environmental Science and Engineering, Indian Institute of Technology (ISM) Dhanbad-826004 Jharkhand, India 4 Institut fuer Technische Chemie, Leibniz Universitat Hannover, Callinstrasse 3, D-30167 Hannover, Germany e-mail: [email protected]

Abstract: The consistent efforts over past years in synthesizing semiconductors as a promising photocatalysts for environment remediation have made significant achievements. With the recent embarkment of organic polymeric semiconductor graphitic carbon nitride (g-C3N4) has twisted research activates of light driven energy materials in new direction and dimension. This specific material exhibits high command on utilising the visible light and also widely abundant elements with notable environmental stability. However there are notable limitations on the either of the semiconductor categories and needs to be resolved through the possible routes. Henceforth we amalgamated perovskite SrTiO3 with said organic photocatalyst for mutural improvement of the photocatalyst through a symbiotic interaction. The ineraction between the photocatalyst and the mobility of free electrons across the junction of g-C3N4/SrTiO3 were revealed. The comprehensive materials investigation and analysis clearly revealed that amalgamation stimulated the utilization of solar spectrum by enhancing the light absorption towards visible spectrum. The perovskite well promoted close interfacial connections leading to enhanced efficiency of electron migration. The solar photocatalysis experiments clearly revealed the robustness of the developed composites by eliminating Bisphenol A, a well know Endocrine Disruptive Compound(EDC) of nonphotosensitising category from aquatic stream.

Keywords: pervoskite• g-C3N4• amalgamation • solar photocatalysis • Bisphenol A [1] S. Samanta, S. Martha, K. Parida, Chem.Cat.Chem., 2014, 6, 1453-1462 [2] P. T. Anastas, M. M. Kirchhoff, T. C. Williamson, Appl. Catal. A-Gen., 2001, 221, 3-13. [3] P.S. Yap, T.T. Lim, M. Lim, M. Srinivasan, Catal. Today, 2010, 151, 8-13. [4] M. R. Hoffmann, S. T. Martin, W. Choi, D. W. Bahnemann, Chem. Rev., 1995, 95, 69-96. [5] Z. Zhao, Y. Sun, F. Dong, Nanoscale, 2015, 7, 15-37

45

Wuhan, China

Invited Lecture IL3

Synthesis of efficient graphene- and C3N4-based photocatalysts Yang Qu and Liqiang Jing* Key Lab of Functional Inorganic Materials Chemistry (MOE), School of Chemistry and Materials Science, Heilongjiang University, Harbin City 150080, China. E-mail: [email protected]

Abstract: It is highly desired to improve the photocatalytic performance for pollutant degradation and energy production. For this, three synthetic strategies have been successfully developed for improved photocatalysis as follows. Firstly, N doping into graphene could promote O 2 adsorption so as to improve the photocatalytic activity for degrading pollutants of graphene/Fe 2O3 nanocomposites. Secondly, the surface polarization by modifying negative anions, like Cl -, could trap positive holes so as to improve the photocatalytic activities. Lastly, the proper-level-energy platform by coupling wide-bandgap nano-oxides, like SnO2, could accept the excited proper-levelenergy electrons from the narrow-bandgap semiconductors, like g-C3N4 and B,P-codoped one, so as to prolong the carrier lifetime and thereby improve the visible-light photocatalytic activities for pollutant degradation and CO2 conversion, along with expanded visible-light range. Meanwhile, the mechanism insights have been explored in details based on the atmosphere-controlled surface photovoltage spectra, time-resolved surface photovoltage responses, photoelectrochemical measurements, O2 temperature-programmed desorption and electrochemical reduction curves. These works would provide feasible routes to improve the photocatalysis for efficiently degrading pollutants and producing energy. Acknowledgements: This work was financially supported from the key NSFC (U1401245, 91622119), the National Key Basic Research Program of China (2014CB660814), the Program for Innovative Research Team in Chinese Universities (IRT1237).

Keywords: g-C3N4• graphene • Synthesis• Charge property • photocatalysis [1] L. Q. Jing*, J. Zhou, J. R. Durrant, et al., Energy Environ. Sci., 2012, 5, 6552-6558. [2] L. Q. Jing, W. Zhou, G. H. Tian, H. G. Fu*, Chem. Soc. Rev., 2013, 42, 9509-9523. [3] L. M. He, L. Q. Jing*, Y. B. Luan, et al., ACS Catal., 2014, 4, 990-996. [4] Z. J. Li, Y. B. Luan, L. Q. Jing*, et al., ACS Appl. Mater. Interface 2015, 7, 22727-227. [5] A. Zada, M. Humayun, L. Q. Jing*, et al., Adv. Energy Mater., 2016, 4, 1601190 (1-9). [6] M. Humayun, Y. Qu, L. Q. Jing*, et al., Environ. Sci. Tech., 2016, 50, 13600-13610. [7] F. Raziq, Y. Qu, L. Q. Jing*, et al., J Phys. Chem. C 2016, 120, 98-107. [8] F. Raziq, Y. Qu, L. Q. Jing*, et al., Appl. Catal. B 2017, 201, 486-494. [9] Z. J. Li, Y. Qu, L. Q. Jing*, et al., Appl. Catal. B 2017, 203, 355-362.

46

Wuhan, China

Invited Lecture IL4

New strategies to enhance the photocatalysis of g-C3N4: alkalis mediated vertical channel and size-dependent Bi metal deposition Fan Dong*,a, Wanglai Cen b, Guangming Jiang a, Jieyuan Li b, Wen Cui a, Ting Xiong a a

Chongqing Key Laboratory of Catalysis and New Environmental Materials, College of Environment and Resources, Chongqing Technology and Business University, Chongqing 400067, China. b Institute of New Energy and Low Carbon Technology, College of Architecture and Environment, Sichuan University, Chengdu 610065, China. E-mail: [email protected]

Abstract: Graphitic carbon nitride (g-C3N4) has been widely investigated and applied in photocatalysis and catalysis, but its performance is still unsatisfactory. We have developed two new strategies to enhance the photocatalysis of g-C3 N4: alkalis mediated vertical channel and sizedependent Bi metal deposition, providing new insights into the g-C3N4 photocatalysis. Adopting alkalis intercalation, we have developed a feasible strategy to accelerate the photocatalysis efficiency of g-C3N4, and shoved the gate to detailed understanding of the charge separation mechanism at atomic level. It is first found that Rb doping enormously facilitates the photocatalysis efficiency of g-C3N4, significantly exceeding that of the bare and the other alkalis doped ones. Also revealed is that the enhanced photocatalytic performance of g-C3N4 crucially depends on three conclusive aspects: 1) appropriate distance of g-C3N4 layers to develop the function of foreign atoms as mediation for interlayered electrons migration, also impede the unwished accumulation of reaction products (Fig. 1); 2) efficient quenching of the fast charge carriers recombination in g-C3N4 planes and 3) the directional electrons delivery through the solid interlayered channel to suppress the recombination between layers (Fig. 2). This work provides new perspectives for the targeted design and fabrication of high-efficiency 2D photocatalysts. We have presented one facile approach to fabricate the monodisperse size-controlled Bi NPsdecorated g-C3N4, which is highly effective and durable for the visible light photocatalytic removal of ppb-level NO in a continous air flow under room temperature. The decoration of Bi NPs could significantly promote the performance of the g-C3N4, which should be ascribed to the construction of the heterojunction between Bi NPs and g-C3N4, and the SPR effect of Bi NPs (Fig. 3). The contribution of heterojunction effect and the SPR effect of Bi NPs depends much on the Bi NP size. At a small size, the heterojunction effect dominates, otherwise the SPR effect will take the leading role. On the catalyst surface, the photoexcited e- will transform into the •O2- and •OH, which serve as the leading radicals with the photoexited h+ participating in NO oxidation. The NO will finally be oxidized to the bidentate and monodentate nitrate and accumulated on surface of the photocatalyst as revealed with DRIFTS. The present work could provide new perspectives into the designed synthesis of structure-controlled photocatalysts and application of the photocatalysis. Fig. 1

Fig. 2

Fig. 3

Keywords: g-C3N4 • Photocatalysis • Charge separation • NO purification • Reaction Mechanism [1] F. Dong*, Z. Zhao, Y. Sun, Y. Zhang, S. Yan*, Z. Wu, Environ. Sci. Technol., 2015, 49, 12432-12440. [2] T. Xiong, W. Cen, Y. Zhang, F. Dong*, ACS Catal., 2016, 6, 2462-2472. [3] F. Dong*, T. Xiong, S. Yan, H. Wang, Y. Sun, Y. Zhang, H. Huang, Z. Wu*, J. Catal., 2016, 344, 401-410. [4] G. Jiang, X. Li, M. Lan, T. Shen, X. Lv, F. Dong*, S. Zhang*, Appl. Catal. B: Environ., 2017, 205, 532-540.

47

Wuhan, China

Invited Lecture IL5

Visible-light driven photocatalytic CO2 reduction using g-C3N4 nanosheets/Fe MC heterogeneous catalysts Lin Lin, Xuehua Zhang, and Tao He* CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, China e-mail: [email protected]

Abstract: Photocatalytic reduction of CO2 into value-added chemicals is particularly attractive, as it can produce renewable energy and capture greenhouse gas [1-3]. Photocatalysts based on g-C3N4 and its composites with molecular catalysts (such as Fe MC) have shown great potential in solar driven water splitting and CO2 reduction by virtue of the high chemical and thermal stability, suitable band alignment, low cost, and easy synthesis of [4-6]. Here we report high efficient visiblelight driven photoconversion of CO2 into CO using g-C3N4 nanosheets/Fe MC heterogeneous catalysts. The g-C3N4 nanosheets act as the light harvesting unit and Fe MC works as the catalytic center. It is found that the photo-induced electrons can efficiently transfer from g-C3N4 to Fe MC. The as prepared g-C3N4/Fe MC heterogeneous catalysts exhibited remarkable photocatalytic activity for CO production via CO2 reduction. A possible mechanism for CO2 reduction was also proposed. We envision that this may facilitate the R&D of high-efficient photocatalysts, as well as affording a better understanding of the related mechanism for the photoreduction of CO 2. Keywords: CO2 • photoreduction • g-C3N4 nanosheet • Fe molecular catalyst • charge transfer [1] [2] [3] [4] [5] [6]

T. Inoue, A. Fujishima, et al, Nature, 1979, 277, 637-638. F. Bi, T. He, et al, Chin. J. Chem., 2015, 33, 112-118. M. F. Ehsan, T. He, Appl. Catal. B, 2015, 166-167, 345-352. X. C. Wang, K. Maeda, et al, Nat. Mater., 2009, 8, 76-80. Y. Huang, T. He, et al, RSC Adv., 2015, 5, 33254-33261. J. Bonin, M. Robert, et al, J. Am. Chem. Soc., 2014, 136, 16768-16771.

48

Wuhan, China

Invited Lecture IL6

Ultrasonic Spray Pyrolyzed TiO2/Keggin POMs Microspheres for CO2 Photoreduction Changhua Wang, Han Zheng, Xintong Zhang* and Yichun Liu Address: Department of Physics, Northeast Normal University, Changchun, China e-mail: [email protected]

Abstract: Proton coupled electron transfer (PCET) in terms of multielectron and multiproton is ubiquitous in energy conversion and storage reactions in chemistry and biology. For artificial photosynthesis, however, a particular challenge is to efficiently couple multielectron and multiproton transfer processes in CO2 reduction and H2O oxidation.[1-3] We explore here the possibility of PCET for CO2 photoreduction over Keggin type polyoxometallates (POM) grafted TiO2 microspheres by ultrasonic spray pyrolysis. Structural analysis reveals that as-adopted assembly process ensures a high dispersion of POM on TiO2 and endows composites with enriched surface hydroxyl groups and high packing density of nanoparticles. Whereas pristine TiO 2 seems inert in production of CH4 via PCET in reduction of CO2, optimal surface grafting of POM (12tungstophosphatic acid) exceptionally results in high generation rate of CH4 of ca. 0.1 μmol/g/h without any sacrificial reagent. The high activity of POM/TiO2 is believed to originate from a multielectron transfer dominated by POM/TiO2 interface and a multi-proton transfer governed by enriched surface hydroxyl groups after a comprehensive analysis on the basis of XPS, transient photovoltage, photochromic phenomenon and sacrificial reagent incorporated photocatalytic characterizations.

CO2 CO, CH4

ee-

O

e-

Ti e-/h+

CO2

e-

e- O e-/h+

CO, CH4

Tiee-/h+

e-

O

e-

e-/h+

Ti e-/h+

Ti

CO, CH4

e-

e-/h+

Keywords: multielectron transfer; multiproton transfer; CO2 reduction; POM [1] [2] [3]

e-CO2

J. Low, J. Yu, W. Ho, J. Phys. Chem. Lett., 2015, 6, 4244. A. Fujishima, X. T. Zhang, D.A. Tryk, 2008, 63, 515. C.H. Wang, X.T. Zhang, Y.C. Liu, Appl. Surf. Sci., 2015, 358, 28.

49

Wuhan, China

Invited Lecture IL7

Copper and copper oxides based materials for CO2 photo(electro)chemical conversion to organic fuel** Luo Yu, Xin Ba, Guodong Shi, Yanfang Li, Wenpei Zhang and Ying Yu* College of Physical Science and Technology, Central China Normal University, Wuhan, China e-mail: [email protected]

Abstract: The most important issue for CO2 conversion under renewable energy is catalytic materials with high efficiency. So far, Cu and CuOx materials have been widely applied as catalysts for electrochemical, photochemical and photoelectrochemical CO 2 conversion. What we have done is as follow. Firstly, we modified TiO2 nanotubes (TNTs) with Cu2O. The prepared composites with varying amounts of Cu2O were exploited for the photocatalytic reduction of CO2 in the presence of water vapor under visible and simulated solar irradiation. The photocatalyst containing an optimized Cu2O content exhibited a significantly higher hydrocarbon production efficiency than that of pure TNTs.[1] Secondly, In order to overcome the instability shortage of Cu 2O, a “hitting three birds with one stone” strategy has been proposed to synthesize carbon layer coated Cu 2O mesoporous nanorods on Cu foils via a facile chemical oxidation and subsequent carbonization method. The thin carbon layer not only worked as a protective layer to quench the common photocorrosion problem of Cu2O, but also endowed the sample a mesoporous and one-dimensional nanorod structure. Substantially, the coated samples exhibited remarkably improved stability as well as decent activity for CO2 reduction under visible light irradiation.[2] Thirdly, we have accomplished better conversion of CO2 by the combination of metal electrode and Cu2O semiconductor thin film. The prepared Cu/Cu2O samples had much higher selectivity for C2H4 formation compared with pure Cu electrode although CH4 and C2H4 were the major hydrocarbon gas products. The best yield for CO2 reduction was obtained in photoelectrochemical system under visible light. Moreover, CO2 conversion efficiency over Cu/Cu2O (p-type) electrode was much higher than that over Cu/Cu2O (n-type) with similar morphology. The morphology of Cu 2O had effect on the CO2 reduction activity as well.[3] Finally, we used copper nanoparticles to modify MoS2 nanoflowers. The optimal hierarchical Cu/MoS2 composite not only exhibited remarkably enhanced electronic conductivity and specific surface area but also possessed improved CO 2 absorption capacity, resulting in a significant increase in overall faradaic efficiency and a 7-fold augment for the faradaic efficiency of CH4 compared with bare MoS2. Moreover, the Cu/MoS2 composite had a superior stability with high efficiency retaining for 48 h in electrochemical process.[4]

Keywords: Copper and copper oxides• CO2 conversion to organic fuel• photo(electro)chemistry • [1] [2] [3] [4]

Y. Li, W. Zhang, X. Shen, P. Peng, L. Xiong and Y. Yu, Octahedral Cu 2O modified TiO2 nanotube arrays with high efficiency in photocatalytic reduction of CO2, Chin. J. Catal. 2015, 36, 2229-2236. L. Yu, G. Li, X. Zhang, X. Ba, G. Shi, Y. Li, P.K. Wong, J. C. Yu, and Y. Yu, ACS Catal. 2016, 6, 6444-6454. X. Ba, L. Yan, S. Huang, X. Xia and Y. Yu, J. Phys. Chem. C, 2014, 118, 24467-24478 G. Shi, L. Yu, X. Ba, X. Zhang, J. Zhou and Y. Yu, Dalton Trans. 2017, DOI: 10.1039/c6dt04381j.

50

Wuhan, China

Invited Lecture IL8

Fabrication of TiO2 nanorod assembly grafted rGO (rGO@TiO2-NR) hybridized flake-like photocatalyst ** Kangle Lv*, Shun Fang, Lingling Si, Wingkei Ho* Address: Key Laboratory of Catalysis and Materials Science of the State Ethnic Affairs Commission and Ministry of Education, College of Resources and Environmental Science, South-Central University for Nationalities, Wuhan, China. e-mail: [email protected] (K. Lv), [email protected] (W.K. Ho)

Abstract: Fabrication of TiO2 nanorod assembly grafted rGO (rGO@TiO2-NR) hybridized flakelike photocatalyst. To efficiently separate the photo-generated electron–hole pairs of TiO2 hybrid, anatase TiO2 nanorod assembly grafted reduced graphene oxides (rGO@TiO2-NR) hybrid was successfully fabricated using potassium titanium oxalate (PTO) and graphene oxides (GO) as starting materials and diethylene glycol (DEG) as reductant. The effect of GO content on the structure and photocatalytic activity of rGO@TiO2-NR composite was systematically studied. Results show that, in the absence of GO, only TiO2 microsphere assembly is obtained from TiO2 nanorods. The presence of GO results in the formation of a flake-like TiO2-nanorod-assembled grafted rGO hybrid. The photocatalytic activity of rGO@TiO2-NR composite increases first and then decreases with increase in the amount of GO from 0 wt.% to 10 wt.%. The hybridized S4 sample prepared with 4 wt.% GO possesses the highest photocatalytic activity with a constant rate of 0.039 min−1 in the photocataytic degradation of Brilliant X-3B dye (X3B); this sample was enhanced more than three times when compared with pure TiO 2 sample (0.012 min−1). The enhanced photocatalytic activity of the rGO@TiO2-NR hybrid was attributed to the strong interaction between TiO2 nanorods and rGO. The unique hierarchical structure of 1D nanorod assembly TiO2–rGO flakes facilitates the injection and transfer of photo-generated electrons from TiO2 to graphene, thus retarding the recombination of electron–hole pairs and enhancing the photocatalytic activity. The enlarged BET surface areas, not only increasing the number of active sites, but also facilitating the adsorption of the dye, and improved light-harvesting ability also contribute to the enhanced photoreactivity of rGO@TiO2-NR hybrid.

Scheme 1. Schematic comparing the packing modes of (a) 1D TiO2 nanorods and (b) 0D TiO2 nanoparticles on graphene nanosheet with similar TiO2 loading amounts. Inset showing that (1) 1D TiO2 nanorods can efficiently inject the photo-generated electrons to graphene and that (2) the exposure of graphene is beneficial for the transfer of electrons from graphene to dissolved oxygen and the formation of reactive oxygen species. Keywords: TiO2 • graphene oxide • photocatalytic degradation • hybrid [1] Q.J. Xiang, B. Cheng, J.G. Yu, Angew. Chem. Int. Ed., 2015, 54, 11350-11366. [2] Kangle Lv, Shun Fang, Lingling Si, Yang Xia, Wingkei Ho, Mei Li, Appl. Surf. Sci., 2017, 391, 218-227. [3] X.Y. Zhang, H.P. Li, X.L. Cui, Y.H. Lin, J. Mater. Chem. 2010, 20, 2801-2806.

51

Wuhan, China

Invited Lecture IL9

Facet effect of metal cocatalyst on solar-to-fuel conversion over semiconductor photocatalysts** Shaowen Cao* State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, 122 Luoshi Road, Wuhan 430070, P. R. China e-mail: [email protected]

Abstract: The separation and transfer of charge carriers, adsorption of reactant molecules, and

desorption of product molecules are crucial factors that affect the photocatalytic process. Herein, we demonstrate the significant facet effect of metal cocatalyst toward photocatalytic H2 evolution and CO2 photoreduction over semiconductor photocatalysts. The surface atomic structure of Pt or Pd cocatalyst can be precisely controlled by adjusting the amount of {111} and {100} facets to modulate the interfacial charge carrier transfer, molecule adsorption and desorption. It is shown that the metal nanocrystals with exposed {111} facets function as a more efficient cocatalyst as compared to metal nanocrystals with exposed {100} facets, which is reflected by enhancing the photocatalytic H2 evolution and CO2 photoreduction over semiconductor photocatalysts. The origin of such remarkable shape-induced effect is explained on the basis of experimental studies of charge transfer dynamics and the atomic-scale DFT modelling of molecule adsorption and desorption.

Keywords: Surface structure • metal cocatalyst • photocatalysis • solar-to-fuel conversion [1] [2] [3]

S. W. Cao, F. Tao*, Y. Tang, Y.T. Li, J. G. Yu*, Chem. Soc. Rev., 2016, 45, 4747-4765. S. W. Cao, Y. Li, B. C. Zhu, M. Jaroniec, J. G. Yu*, J. Catal., 2017, accepted. S. W. Cao, J. Jiang, B. C. Zhu, J. G. Yu*, Phys. Chem. Chem. Phys., 2016, 18, 19457-19463.

52

Wuhan, China

Invited Lecture IL10

Raman spectroscopy and Raman imaging for assessing and studying catalytic materials Shurong Ma*, Ying Xie and Yanliang Zhang Address: Molecular Spectroscopy, Thermo Fisher Scientific Inc, Beijing, China e-mail: [email protected]

Abstract: Raman spectroscopy and imaging are known to be valuable tools for the analysis of materials, from organic compounds to inorganic materials. Raman technology provides a fast and non-destructive tool to help study the molecular structure of chemicals and materials. The main content of this report is to share some recent researches by leveraging Raman spectroscopy and Imaging technology to help assess and study catalytic materials. Raman spectrum was commonly used to identify and confirm the catalyst and support[1]. In-situ Raman can help analyze the catalytic performance of the catalysts in catalytic reaction process[2]. By analyzing the adsorption of molecular sieve and catalyst by Raman helps explore the mechanism of surface adsorption. The most important application, the research of the overall change and uniformity of catalytic materials has applied the latest ultra fast Raman Imaging technology, and this research has brought the catalyst research to a further level.

Keywords: Raman • Imaging • catalytic materials [1] W.D Shi et al. Langmuir 2016, 32, 1629−1636. [2] E. Venardou et al. Vibrational Spectroscopy 35 (2004) 103–109.

53

Wuhan, China

Invited Lecture IL11

Photocatalytic carbon cycling for controlling organic pollution and reducing CO2 emission Shengwei Liu1,* and Jiaguo Yu2 Address: 1School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510006, China E-mail: [email protected] 2State Key Laboratory of Advanced Technology for Material Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, P. R. China

Abstract: In recent years, the excessive discharge of a variety of organic compounds into the environment, including POPs in water and VOCs in air, has raised worldwide concerns of environmental pollution. An interesting protocol for organic pollution is to convert toxic organic compounds into harmless CO2 by photocatalytic oxidation processes. Meanwhile, the atmospheric concentration of CO2 as one of the dominant greenhouse gas continues to rise and has become a global climate and ecological issue. Reducing CO2 emission by photocatalytic resourcing the greenhouse gas CO2 into useful chemicals or fuels attracted great attentions. The versatile photocatalytic processes has emerged as one of the most potential route for carbon neutrality through the photocatalytic carbon cycling. To some extent, the photoactive mineral on earth shall contribute to the carbon cycling and maintain the carbon equilibrium.

Figure 1 The carbon cycling during photocatalytic processes Keywords: Photocatalysis • dye degradation • bacterial disinfection • VOC removal• CO2 reduction [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12]

J.G. Yu*, S.W. Liu, H.G. Yu , J. Catal., 2007, 249, 59-66. S. W. Liu, J. G. Yu*, M. Jaroniec*, J. Am. Chem. Soc., 2010,132, 11914-11916. J.G. Yu, T.T. Ma, S.W Liu, Phys. Chem. Chem. Phys., 2011, 13, 3491-3501. S. W. Liu, C. Li, J. G. Yu* and Q. J. Xiang, CrystEngComm, 2011, 13, 2533-2541. S. W. Liu, J. G. Yu*, M. Jaroniec*, Chem. Mater., 2011, 23, 4085-4093. S. W. Liu, J. G. Yu*, B. Cheng, M. Jaroniec*, Adv. Colloid Interface Sci., 2012, 173, 35-53. S. W. Liu, K. Yin, W. S. Ren, B. Cheng, J. G. Yu*, J. Mater. Chem., 2012, 22, 17759-17767. S. W. Liu, C. Liu, W.G. Wang, B. Cheng, J. G. Yu, Nanoscale, 2012, 4, 3193-3200. J.G. Yu*, Q. Li, S.W. Liu, M. Jaroniec, Chem. Eur. J., 2013, 19, 2433-2441. S. W. Liu, G. C. Huang, J. G. Yu*, T. W. Ng, H. Y. Yip, P. K. Wong*, ACS Appl. Mater. Interfaces, 2014, 6, 2407-2414. S. W. Liu*, J. Q. Xia, J. G. Yu*, ACS Appl. Mater. Interfaces, 2015, 7(15), 8166-8175. S.W. Liu,* J.H. Wang and J.G Yu*, RSC Adv., 2016, 6, 59998–60006.

54

Wuhan, China

Invited Lecture IL12

O-doping and Nanoporous Graphitic Carbon Nitride for Enhanced Hydrogen Evolution ** Jing-Wen Zhang, and Ji-Jun Zou * Key Laboratory for Green Chemical Technology of the Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China [email protected] (Ji-Jun Zou)

Abstract: Efficient charge separation and broaden light absorption are of crucial importance for solar driven hydrogen evolution reaction (HER), and graphitic carbon nitride (g-C3N4) is a very promising photocatalyst for this reaction. Here we report two facile precursor pre-treatment methods, by forming hydrogen bond-induced supramolecular aggregates, to fabricate g-C3N4 with simultaneous novel porous network and controllable O-doping. Experimental and DFT computation identified that O doping preferentially occurs on two-coordinated N position, and the porous network and O-doping synergetically promote the light harvesting and charge separation. As a result, the g-C3N4 synthesized from H2O2-treated melamine shows 6.1 higher HER activity (with apparent quantum efficiency of 7.8% at 420 nm) than bulk and even 3D porous g-C3N4. The g-C3N4 fabricated from hydrothermal precursor achieves 11.3 times activity of bulk g-C3N4. This work highlights that simply pre-treating the precursor can not only control the architecture but also introduce helpful foreign atoms or monomer in the matrix, which provides a useful strategy to design and fabricate highly efficient g-C3N4 photocatalyst.

Keywords: Photocatalysis • Carbon nitride • Porous network • O-doping • Hydrogen evolution [1] Huang, Z.-F., et al., Carbon nitride with simultaneous porous network and O-doping for efficient solar-energy-driven hydrogen evolution. Nano Energy, 2015. 12: p. 646-656 [2] Tahir, M., et al., Efficient water oxidation through strongly coupled graphitic C 3N4 coated cobalt hydroxide nanowires. J. Mater. Chem. A, 2016. 4(33): p. 12940-12946.

55

Wuhan, China

Invited Lecture IL13

Fish-scale Structured g-C3N4 Nanosheet with Unusual Spatial Electron Transfer Property for High-Efficiency Photocatalytic Hydrogen Evolution Bo Lin a, Hua An a, Xiaoqing Yan a, Tianxi Zhang a, Jinjia Wei a, Guidong Yang*a Department of Chemical Engineering, School of Chemical Engineering and Technology, Xi’an Jiaotong University, Xi’an 710049 (P.R. China). E-mail: [email protected] (Guidong Yang)

a

Abstract: Grafing the structures in nature onto g-C3N4 is an interesting and fascinating protocol to highly optimize its performances[1-6]. Herein, a novel opened-up fish-scale structured g-C3N4 nanosheet has been synthesized via a simple one-step solvothermal method for photocatalytic hydrogen evolution (Figure 1). The unique fish-scale structure endows g-C3N4 with intimate spatial electron transfer property, which means that the photogenerated electrons selectively migrate along the flat direction to the edges of fish-scale flakes. This property well reveals the transfer path of photogenerated charges and the origin of high charge separation efficiency in photocatalytic reaction, thus yielding a remarkable catalytic activity (a hydrogen-evolution rate of 1316.35 μmol h1 -1 g ), nearly 20 and 2.93 times higher than that of bulk g-C3N4 and exfoliated g-C3N4 nanosheet. Besides, the fish-scale structured g-C3N4 also owns a superior durability and stability, indicating an outstanding potential application in solar fuel production. The research results would provide a platform for the design and construction of high-performance photocatalysts with highly-efficient charge separation.

a

b

ac

d

e

f

Figure 1 SEM images of (a) BCN, (b) CNNs, (c) FSGNs1, (d) FSGNs2 and (e) FSGNs3. EDX image (f) of FSGNs2. The strong signal peak of Si is derived from the silicon substrate with the uniformly loaded sample in the SEM test.

Keywords: Fish-scale, g-C3N4, Nanosheet, Unusual spatial electron transfer, Photocatalytic Hydrogen Evolution. [1] [2] [3] [4] [5] [6]

Y. Zheng, L. H. Lin, X. J. Ye, F. S. Guo, X. C. Wang, Angew. Chem. Int. Ed. 53 (2014) 11926-11930. W. Z. Wang, J. Xu, ACS Appl. Mater. Interfaces 7 (2015) 415-421. J. Zhu, K. Y. S. Ng, D. Deng, ACS Appl. Mater. Interfaces 6 (2014) 2996-3001. B. Lin, G. D. Yang, B. L. Yang, Y. X. Zhao, Appl. Catal. B: Environ. 198 (2016) 276-285. W. H. Wang, J. Y. Dong, X. Z. Ye, Y. Li, Y. R. Ma, L. M. Qi, Small 12 (2016) 1469-1478. J. S. Zhang, M. W. Zhang, C. Yang, X. C. Wang, Adv Mater 26 (2014) 4121-4126.

56

Wuhan, China

Invited Lecture IL14

Photocatalytic Hydrogen Production of Palladium Nanoparticles Decorated Black TiO2 Calcined in Argon Atmosphere Yin-Hsuan Chang, Kai-Chi Hsiao, Po-Yeh Wu, Shun-Hsiang Chan, and Ming-Chung Wu* Department of Chemical and Materials Engineering, College of Engineering, Chang Gung University, Taoyuan 33302, Taiwan *e-mail: [email protected]

Abstract: The recent discovered “black TiO2” nanoparticles (BTN) has gathered a lot of interests for its visible light absorption capability. [1-3] Hydrogen reduction[4,5] were developed to produce the disorder-engineered BTN and causes the lattice disorder in TiO2 nanoparticles based on the highly localized nature of the midgap states that results in spatial separation of photoexcited electrons and holes in BTN.[6] Compared with white titanium dioxide nanoparticles (WTN), BTN can be expect to possess the higher utility of solar light, and much potential in pratical application. However, BTN was usually prepared under the high hydrogen pressure condition in a long calcination time. Since hydrogen gas is flammable, the preparation process with high pressure arises public safety worries.[7] The objective of this study is to obtain a high photocatalytic activity BTN in a moderate secure process. Thus, we demonstrated that a series of BTN was prepared by sol-gel method and followed by calcination at different temperature in the flow of Argon. For the preparation of BTN, titanium isopropoxide and n-propanol were mixed well at ambient temperature. The gelation was conducted as hydrochloric acid and deionized water both added. The derived gel was calcined separately at various temperatures of 350, 400, 450, 500, 500 and 600 °C for 2 h in argon atmosphere. The obtained BTN was further decorated with palladium by wet-impregnation method in order to improve the ability of photocatalytic hydrogen production. The properties such as crystalline, microstructure, optical behavior and chemical composition were characterized as well. The synthesized BTN with trivalent titanium, oxygen vacancies and structural defects shows a remarkably high absorbance at visible wavelength. BTN thus behaves a higher visible-active nanoreactor than WTN in the aqueous solution for organic pollutant degradation. Moreover, palladium decoration on the BTN surface (Pd-BTN) demonstrates a fascinating clean energy application. The obtained Pd-BTN fulfils a satisfied green material demand in the photocatalytic hydrogen production application. Pd-BTN calcined at 400oC (Pd-BTN-400) shows the high photocatalytic hydrogen generation rate of 5,200 μmol/g·hr under UV-A irradiation and 9,300 μmol/g·hr under UV-B irradiation, respectively. The well-developed material, Pd-BTN-400, could be one of the best solution in the concern of clean energy and water-purification with regard to the continuous environmental health. Keywords: hydrogenation • TiO2 • photocatalytic hydrogen production • photodegradation • sol-gel method [1] X. Chen, L. Liu, P. Y. Yu, S. S. Mao., Science, 2015, 331, 746-750 [2] T. Xia and X. Chen, J. Mater. Chem. A, 2013, 1, 2983-2989 [3] J. Zhaoa, Y. Lia, Y. Zhua, Y. Wang, C. Wang, Appl. Catal., A, 2016, 510, 34-41 [4] Y. Yan, M. Han, A. Konkin, T. Koppe, D. Wang, T. Andreu, G. Chen, U. Vetter, J. R. Morantee, and P. Schaafa, J. Mater. Chem. A, 2014, 2, 12708-12716 [5] E. M. Samsudina, S. B. A. Hamida, J. C. Juana, W. J. Basiruna,and A. E. Kandjanib, Appl. Surf. Sci., 2015, 359, 883-896 [6] L. Liu, P. Y. Yu, X0 Chen, S. S. Mao, and D. Z. Shen, Phys. Rev. Lett., 2013, 111, 065505 [7] X. Chen, L. Liub, and F. Huang, Chem. Soc. Rev., 2015, 44, 1861-1885

57

Wuhan, China

Oral Lectures

58

Wuhan, China

59

Wuhan, China

Oral Lecture OL1

Preparation of graphene-photocatalyst hydrogel composite and its application for the removal of organic contaminant Daimei Chen School of Materials Sciences and Technology, China University of Geosciences, Beijing, China E-mail: [email protected];

Abstract: Environmental pollution problems have become increasingly serious with the rapid development of human society, especially the water pollution, which seriously affects our daily life [1–3]. It is well known that the adsorption method is one of the widely used strategies for the treatment of water pollution due to its advantages of low cost, high adsorption capacity, high adsorption rate and ease of operation. Among diverse of adsorption materials, the 3D network structure of hydrogel, especially the 3D structural graphene has attracted much attention because it can reduce the aggregation and provide multidimensional mass transmission channel, and it is easy to separate from the mixture reaction solution. Although the absorption method is regarded as an effective method for water treatment, the hazardous water pollutants are just concentrated rather than mineralized to non-polluting sub-stances by adsorption material. It might cause secondary pollution in waste water treatment. Furthermore, the adsorbents are generally difficult to regenerate and need to be treated to release the pollutant when reached their saturations. Therefore, it is necessary to develop the new technology to remove the hazardous pollutants from water. The combination of 3D structural hydrogel with photocatalyst to fabricate the 3D porous hydrogel-based composite photocatalyst can not only overcome the adsorption saturation and nonregeneration problems of adsorption material, but also can improve the adsorption property and the separation of powder photocatalysts. In our work, a novel visible-light 3D-3D Bi2 WO6/graphene hydrogel (BWO/GH) photocatalyst with the synergistic effect of adsorption and photocatalysis has been successfully synthesized and is applied in environment remediation. The construction of BWO/GH composite resolved the adsorption saturation problem of GH and improved the photocatalytic activity of BWO, thus greatly improved the removal rate of water pollutants.

[1] Z. Tong, D. Yang, J. Shi, Y. Nan, Y. Sun, Z. Jiang, ACS Appl. Mater. Interfaces, 2015, 7, 25693–25701. [2] Y. Fan, W. Ma, D. Han, S. Gan, X. Dong, L. Niu, Adv. Mater. 2015, 27, 3767–3773. [3] J. Yang, D. Chen, Y. Zhu, Y. Zhang, Y. Zhu, Appl. Cataly. B: Environ. 2017, 205, 228–237

60

Wuhan, China

Oral Lecture OL2

Ternary TiO2 nanosheets–graphene–CdSe quantum dots composite as a high efficient visible-light-driven photocatalyst ** Yang Li, and Quanjun Xiang* College of Resources and Environment, Huazhong Agricultural University Wuhan, 430070, P. R. China E-mail: [email protected]

Abstract: The ternary TiO2 nanosheets–graphene–CdSe quantum dots (QDs) composite photocatalysts were synthesized by a precipitation method using the hydrothermally prepared layered TiO2 nanosheets–graphene sheets as supporting matrix and CdSe QDs solution as precursor. During the synthetic process, anatase TiO2 nanosheets with exposed (001) facets were tightly grown on the surface of graphene sheets with face-to-face orientation, and CdSe QDs with an average size of about 3.0 nm were uniformly and closely attached on the layered TiO2–graphene sheets in the presence of molecular linker mercaptopropionic acid. Owing to the genuine structure and constituents, the prepared ternary TiO2–graphene–CdSe QDs composites show great adsorptivity of aromatic dye on graphene, extended visible-light absorption range by CdSe QDs, and efficient charge separation rate using TiO2 nanosheets as an electron mediator. Hence, the TiO2–graphene– CdSe QDs composites show a highly visible-light photocatalytic activity and stability for the degradation of methylene blue in aqueous solutions. The photocatalytic mechanism is suggested that the CdSe QDs are photoexcited under visible-light irradiation, and the photogenerated electrons are transferred on conduction band of TiO2 as an electron mediator, and then are injected into graphene surface and are accomplished by the reaction of active species. The proposed mechanism was further confirmed by the experiments of transient photocurrent responses, the addition of the scavenger and the detection of ·OH radicals. This work presents that the prepared ternary TiO2– graphene–CdSe QDs composites can be regarded as an ideal photocatalyst for environmental issues due to a great adsorptivity of dyes, and high photocatalytic efficiency and stability.

Keywords: TiO2 nanosheets • CdSe QDs • graphene • photocatalytic activity • visible light [1] [2] [3] [4]

X. Han, Q. Kuang, M. Jin, Z. Xie, L. Zheng, J. Am. Chem. Soc. 131 (2009) 3152-3153. Q.J. Xiang, D. Lang, T.T. Shen, F. Liu, Appl. Catal. B: Environ. 162 (2015) 196-203. Q.J. Xiang, B. Cheng, J.G. Yu, Angew. Chem. Int. Ed. 54 (2015) 11350-11366. Q.J. Xiang, F. Cheng, D. Lang, ChemSusChem 9 (2016) 996-1002.

61

Wuhan, China

Oral Lecture OL3

WO3 catalysed visible light photocatalytic ozonation for wastewater treatment Jin Yang, Yongbing Xie*, and Hongbin Cao Address: Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, China e-mail: [email protected]

Abstract: Semiconductors can trigger a super synergy between photocatalysis and ozonation, and organic pollutants can be effectively mineralized in this combined process [1-2]. It is very important to develop a visible light sensitive catalyst to adopt the green solar energy for the wastewater treatment. In this paper, we synthesized three tungsten oxides (WO3) with different phases and exposed facets and applied them in the visible light photocatalytic ozonation process. These materials were named H-100(hexagonal phase with [100] facet exposed), M-002 (monoclinic phase with [002] facet exposed) and M-100 (monoclinic phase with [100] facet exposed). The activities of the as prepared WO3 materials were evaluated upon cephalexin mineralization in the solution under visible light and ozone bubbling. It was found that M-100 showed the highest activity (Fig.1a). Different optical and electronic properties were characterized. The band gaps (Eg) were calculated from UV-Vis DRS, and the valence bands (VB) were obtained by valence band XPS. The band structures are finally shown in Fig. 1b. As we all know, more negative CB position indicates the generation of electrons with stronger reducing ability and thus favors the reduction reaction [3]. M-100 with more negative CB position can produce electrons with higher ability to reduce ozone molecule to generate reactive radicals. Moreover, Electrochemical Impedance Spectroscopy (EIS) results indicated that the M-100 material has the highest charge transfer ability (b)

(a) 1.0

-2.0

0.9 TOC/TOC0

-1.0

M-100

H-100

M-002

0.8

0.0

0.7

CB 0.19 eV

0.6

Vis/M-100 Vis/M-002 Vis/H-100 Single O3

1.0

0.5

Vis/O3/M-100

2.0

15

30

45

60

75

3.0

90 105 120

2.55 eV

2.28 eV

Vis/O3/H-100

0

0.24 eV

0.40 eV

2.48 eV

Vis/O3/M-002

0.4

CB

CB

2.68 eV

VB

VB

2.79 eV

VB

Time (min)

Figure 1. (a)(c)Mineralization of cephalexin, (b)(d) Band structures of different WO3 materials 1.0

1.0

Switching per 1 h

pH 3.01

TOC/TOC0

TOC/TOC0

pH (5.24) per 0.5 h When adjusting the initial pH fromSwitching 5.24 to 7 or 11, the TOC removal rates Initial were enhanced. A opposite 0.9 pH 7.09 (P.B.) 0.9 Switching per 0.25h pH 11.00 trend was found when the initial pH changed have two different Original to 3.01. It is already known that ozonation 0.8 reaction pathway [4]: 0.8 direct ozonation and indirect radical oxidation. In the acidic media, the formation of 0.7 0.7 from O3 is limited. In the alkaline media, O3 reacts with hydroxyl ion to generate • hydroxyl radicals(•OH) 0.6 OH and it attacks the 0.6 organics at a faster rate. This can well explain the influence of the initial pH. It should 0.5 be noticed that after a period of reaction, the solution became acidic again, no matter it was acidic or basic 0.5 0.4 initially. This was due to the formation of small molecular acid intermediates. To reach a balance of 0.4 high TOC removal rate, a series of 0.3 experiments were conducted to vary the time of economic feasibility and 0 15 30 45 60 75 90 105 120 0 15 30 45 60 75 90 105 120 ozone bubbling. For a total treatingTime time of 2 hours, 1 h ozonation and 1Time h photocatalytic ozonation might be (min) (min) a good choice.

Keywords: WO3 • visible light • photocatalytic ozonation • wastewater treatment J. D. Xiao, Y.B. Xie and H.B. Cao, Chemosphere, 2015, 121, 1-17 E. Mena, A. Rey, S. Contreras and F. J. Beltrán, Catalysis Today, 2015, 252, 100-106. [3] J.D. Xiao, Y.B. Xie, F. Nawaz, S. Jin, F. Duan, M.J. Li and H.B. Cao, Applied Catalysis B: Environmental, 2016, 181, 420-428. [4] M. Pera-Titus, V. Garcıá -Molina, M. A. Baños, J. Giménez and S. Esplugas, Applied Catalysis B: Environmental, 2004, 47, 219-256. [1] [2]

62

Wuhan, China

Oral Lecture OL4

Effect of carbon materials on photocatalytic performance of metal sulfides for H2 production Yang Xia, Qin Li*, Kangle Lv, Mei Li* Key Laboratory of Catalysis and Materials Science of the State Ethnic Affairs Commission & Ministry of Education, South-Central University for Nationalities, Wuhan 430074, P.R. China. E-mail: liqin0518@ mail.scuec.edu.cn (Qin Li); [email protected] (Mei Li)

Abstract: Graphene and its derivative reduced graphene oxide (RGO) have been widely considered to be a miracle modifier for most semiconductor photocatalysts over the past decade. [1] However, the underlying advantage of graphene over its carbon analogs was rarely studied under the same experimental conditions to reveal its uniqueness. [2] In this study, the promotion effect of RGO on ZnIn2S4 (ZIS) semiconductor photocatalyst was systemically compared with that of carbon quantum dots (CQDs) and carbon nanotubes (CNTs). [3] According to the property–photoactivity correlation analysis, the primary roles of these carbon analogs displayed an obvious dissimilarity. Typically, other than low–dimensional CQDs and CNTs, the unique 2D structure of RGO gave rise to a steric hindrance and inhibited the self–assembling process of ZIS nanosheets into microspheres (Figure 1a-h). Therefore, RGO would not be wrapped into the microsphere and be able to expose more surface area than CQDs and CNTs in the composites. The proposed formation mechanism of the obtained composites with different morphologies was displayed in Figure 1i. Such important difference afforded the RGO/ZIS sample improved crystallinity, enhanced light harvest capacity, enlarged specific surface area, increased surface electron concerntration and finally boosted photocatalytic H2 production effeciency than other samples. Interestingly, all the change discipline of the studied properties of the samples followed a same order of RGO/ZIS, CQDs/ZIS, CNTs/ZIS, and ZIS (Figure 1j and 1k). Using 0.3 wt% Pt as cocatalyst and 10 v% triethanolamine aqueous solution as sacrificial reagent, the obtained H 2–production rate of the RGO/ZIS sample was 1.5, 1.6, and 4.2 times higher than that of the CQDs/ZIS, CNTs/ZIS and ZIS samples, respectively (Figure 1l). This work not only highlights the intrinsical role of carbon materials in the enhanced photocatalytic performance of ZIS semiconductor for H2 production, but also provides significant guidance to take full advantage of predominant properties of graphene in designing more efficient photocatalysts.

Figure 1. SEM and TEM images of (a,b) ZIS, (c,d) CQDs/ZIS, (e,f) CNTs/ZIS, and (g,h) RGO/ZIS. (i) Proposed mechanism for the formation of the nanocomposite. Comparison of (j) PL spectra, (k) transient photocurrent responses and (l) H2–production rates of the prepared samples.

Keywords: Graphene • Carbon analogs • ZnIn2S4 • Photocatalyst • Hydrogen production Q. Li, X. Li, J. G. Yu, et al., Adv. Energy Mater., 2015, 5, 1500010. Q. Li, J. G. Yu, et al., Chem. Asian J., 2014, 9, 1766-1770. [3] Y. Xia, Q. Li, K. L. Lv, M. Li, et al., Appl. Catal. B: Environ., 2017, 206, 344–352. [1] [2]

63

Wuhan, China

Oral Lecture OL5

Constructing multi-functional metallic Ni interface layers in the gC3N4 nanosheets/amorphous NiS heterojunctions for efficient photocatalytic H2 generation** Jiuqing Wen a,b, Jun Xie a,b, Xiaobo Chen c, Xin Li a,b * a College of Forestry and Landscape Architecture, Key Laboratory of Energy Plants Resource and Utilization, Ministry of Agriculture, South China Agricultural University, Guangzhou 510642, PR China b College of Materials and Energy, South China Agricultural University, Guangzhou 510642, PR China c Department of Chemistry, University of Missouri – Kansas City, Kansas City, MO, 64110, USA. e-mail: [email protected] (X. Li)

Abstract: Novel graphitic carbon nitride (g-C3N4) nanosheets decorated with multi-functional metallic Ni interface layers and amorphous NiS co-catalysts were fabricated via a facile three-step process: the loading of Ni(OH)2 nanosheets, high-temperature H2 reduction and further deposition of amorphous NiS nanosheets. The as-prepared g-C3N4/Ni/NiS samples were characterized by Xray diffraction (XRD), ultraviolet-visible diffuse reflectance spectroscopy (DRS), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), electrochemical impedance spectroscopy (EIS), polarization curves and Mott–Schottky (MS) plots. The photocatalytic H2 evolution experiments in an aqueous solution of triethanolamine demonstrated that both robust metallic Ni interface layers and amorphous NiS can be utilized as dual-layer electron co-catalysts to markedly enhance the H2-evolution activity over g-C3N4 semiconductor. The optimized g-C3N40.5%Ni-1.0%NiS composite showed the highest hydrogen evolution of 515 µmolg -1·h-1, which was about 2.8 and 4.6 times higher than those of g-C3 N4-1.0%NiS and g-C3N4-0.5%Ni, respectively. It was proposed that the metallic Ni interface layers play multi-functional roles in the enhancement of visible-light H2-evolution performance, which could first collect the photo-generated electrons from g-C3N4, and then accelerate the surface H2-evolution reaction kinetics over amorphous NiS cocatalysts. More interestingly, the synergetic effects of metallic Ni and amorphous NiS dual-layer electron co-catalysts could also boost the TEOA-oxidation capacity through enhancing the VB levels of g-C3N4. Comparatively speaking, the multi-functional metallic Ni layers are dominantly favorable for promoting the separation and transfer of photo-generated charge carriers from g-C3N4 to amorphous NiS co-catalysts owing to the formation of Schottky junctions, whereas the amorphous NiS nanoparticles are mainly beneficial for decreasing the overpotentials for electrocatalytic H2 evolution. It is hoped that the implantation of multi-functional metallic interface layers can become a general strategy to improve their photocatalytic H 2-evolution activity over different semiconductor-cocatalyst heterojunctions. Keywords: Photocatalytic Hydrogen Evolution• dual-layer electron co-catalysts •metallic Ni interface layers• g-C3N4 nanosheets • amorphous NiS [1] [2] [3] [4] [5] [6] [7] [8] [9] [10]

S. Cao, J. Low, J. Yu and M. Jaroniec, Adv. Mater., 2015, 27, 2150-2176. X. Li, J. Yu, J. Low, Y. Fang, J. Xiao and X. Chen, J. Mater. Chem. A, 2015, 3, 2485-2534. J. Wen, X. Li, H. Li, S. Ma, K. He, Y. Xu, Y. Fang, W. Liu and Q. Gao, Appl. Surf. Sci., 2015, 358, 204-212. Y. Zhong, J. Yuan, J. Wen, X. Li, Y. Xu, W. Liu, S. Zhang and Y. Fang, Dalton Trans., 2015, 44, 18260-18269. L. Kong, Y. Dong, P. Jiang, G. Wang, H. Zhang and N. Zhao, J. Mater. Chem. A, 2016, 4, 9998-10007. X. Li, J. Yu and M. Jaroniec, Chem. Soc. Rev., 2016, 45, 2603-2636. K. He, J. Xie, Z. Yang, R. Shen, Y. Fang, S. Ma, X. Chen and X. Li, Catal. Sci. Technol., 2017, DOI: 10.1039/C7CY00029D. J. Wen, J. Xie, X. Chen and X. Li, Appl. Surf. Sci., 2017, 391, 72-123. J. Wen, J. Xie, R. Shen, X. Li, X. Luo, H. Zhang, A. Zhang and G. Bi, Dalton Trans., 2017, 46, 1794-1802. J. Wen, J. Xie, Z. Yang, R. Shen, H. Li, X. Luo, X. Chen and X. Li, Acs Sustain. Chem. Eng., 2017, DOI: 10.1021/acssuschemeng.6b02490.

64

Wuhan, China

65

Wuhan, China

Poster Presentations

66

Wuhan, China

67

Wuhan, China

Poster Presentation PP1

ZnO Nanoflowers with Single Crystal Structure Towards Enhanced Gas Sensing and Photocatalysis Dan Wang*, Sha Zhang, Changchao Jia, Ping Yang, Xin Cheng* School of Material Science and Engineering, University of Jinan, Jinan, Shandong, China, 250022 Shandong Provincial Key Laboratory of Preparation and Measurement of Building Materials, Jinan, Shandong 250022, China E-mail: [email protected], i (X. Cheng). Tel: +86 531 82767655

Abstract: The morphology and surface atomic structure of exposed facets of ZnO materials affect strongly their photocatalyic activity, however, the composite of ZnO and graphene oxide can improve the property. In this paper, ZnO nanoflowers were fabricated by thermal decomposition in an organic solvent and their application in photocatalysis was investigated. These single crystal ZnO nanoflowers with an average size of 60 nm were grown along the {100} facet. It was suggested that oleylamine used in the synthesis inhibited the growth and agglomeration of ZnO through the coordination of the oleylamine N atoms. ZnO–reduced graphene oxide composites were fabricated by loading the ZnO NFs on the surface of the stratiform reduced graphene oxide sheet. In the photodegradation of rhodamine B tests, the composite revealed an enhanced photocatalytic performance compared with ZnO NFs under UV light irradiation. The photogenerated electrons can be transferred from the conduction band of ZnO to RGO, and the RGO serves as an acceptor of electrons and suppresses charge recombination effectively, resulting in higher photocurrent density and more charge carriers to form reactive species, promoting the photodegradation of RhB dyes.[13]

Keywords: graphene oxide, ZnO, photocatalysis, thermal decomposition, single crystal. [1] C. Y. Kuo, J. Hazard. Mater., 2009, 163, 239-244.. [2] L. W. Zhang, H. B. Fu and Y. F. Zhu, Adv. Funct. Mater., 2008, 18, 2180-2189. [3] Q. Liu, Z. Liu, X. Zhang, L. Yang, N. Zhang, G. Pan, S. Yin,Y. Chen and J. Wei, Adv. Funct. Mater., 2009, 19, 894-904..

68

Wuhan, China

Poster Presentation PP2

Enhanced performance in perovskite solar cells via bromide ion substitution and ethanol treatment Bingjie Feng, Jun Zhang, Yang Xu, Zhaosong Li, Hao Wang* Faculty of Physics and Electronic Science, Hubei University, Wuhan 430062, P. R. China e-mail: [email protected]

Abstract: Hybird perovskites have attracted attention over the past few years as absorbers for solar cells [1-2] with power conversion efficiencies (PCEs) exceeding 20% [3]. One of the attractive properties of the hybird perovskites materials is the tunable band gap, which can be achieved by varying the halide composition [4]. So far, several methods were developed to prepare mixed-halide perovskite (MAPbI3-2xBr2x) films such as spinning MAI/MABr blended solution onto the PbI 2 layers [5] or soaking PbI2 layers into MABr solution [6]. In our works, a mixture solution of PbI2 and PbBr2 with different molar ratio are used as lead precursors to obtain mixed lead halide (Pb(I 1xBrx)2) seed layer. To form the mixed perovskite films, MAI molecules are incorporated into the Pb(I1-xBrx)2 network by dipping Pb(I1-xBrx)2 layer into MAI precursors. However, we found the resulted Pb(I1-xBrx)2 layer were densely which could hinder MAI molecules infiltrating and cause incomplete conversion of lead halide to perovskite [7]. Here, ethanol is further employed to treat Pb(I1-xBrx)2 layer to obtain porous structure of it. This phenomenon can be explained that Pb(I1xBrx)2 is insoluble in ethanol but miscible in DMF. When ethanol is dropped onto the Pb(I1-xBrx)2 film, DMF cab be fast extracted and as a result accelerate the crystallization of Pb(I1-xBrx)2. Finally, after ethanol treatment, high quality MAPbI3-xBrx films and enhanced PCE are obtained. A champion device with x = 0.2 in MAPbI3-2xBr2x films obtains PCE of 15.53 % together with 86% of initial PCE after exposed in air condition for 14 days.

Fig.1 SEM top view image illustrating surface morphological evolution of Pb(I 1-xBrx)2 films (a) ~ (e) without ethanol treatment; (f) ~ (j) without ethanol treatment after annealed at 70°C as a function of x value (x = 0, 0.1, 0.2, 0.3 & 0.4 successively).

Keywords: Halide substitution; Ethanol treatment; Perovskite; Stability [1] [2] [3] [4] [5] [6] [7]

S. Aharon, B.E. Cohen, J. Phys. Chem. C., 2014, 118, 17160-17165 D.-X. Yuan, X.-D. Yuan, Phys. Chem. Chem. Phys., 2015, 17, 26653-26658 M. Saliba, T. Matsui, Energy Environ. Sci., 2016, 9 , 1989-1997 D. Bae, A.F. Palmstrom, ACS Appl. Mater. Interfaces, 2016, 8, 14301-14306 J.H. Noh, S.H. Im, Nano lett., 2013, 13 , 1764-1769 K. Cao, H. Li, Nanoscale, 2016, 8, 8839-8846 J.-J. Yan, Y. Li, Superlattices Microstruct., 2016, 94, 196-203.

69

Wuhan, China

Poster Presentation PP3

Template-free fabrication of hierarchical macro/mesoporous SnS2/TiO2 composites Gaopeng Dai1,2,*, Shilong Li1, Zhou Huan1, Cong Pan 1, Suqin Liu1 (1. Department of chemical engineering and food science; Hubei University of arts and science, Xiangyang 441053, China) (2. Hubei Collaborative Innovation Center for Auto Parts Manufacturing Equipment Digitization, Xiangyang 441053, China)

Abstract: Hierarchical macro/mesoporpous SnS2/TiO2 composites were successfully prepared by a hydrothermal method using tetrabutyl titanate as the titanium precursor and stannic chloride as the tin precursor. The prepared samples were characterized by X-ray diffraction (xrd), scanning electron microscopy (SEM), N2 adsorption-desorption isotherms, and UV-visible absorption spectroscopy. The photocatalytic activity of the samples was evaluated by the photocatalytic degradation of Methyl Orange (MO) aqueous solution under simulated sunlight irradiation. The results show that many macroporous were formed in the SnS 2/TiO2 composites. The mesoporous diameter was about 3～9 nm. The macro/mesoporous structure is benefit for the light absorption, organic pollution absorption and transfer. Heterojunction formed between SnS 2 and TiO2 can improve the separated rate of photo-generated carriers. Under the synergistic effect of macro/mesoporous structure and heterojunction, SnS 2/TiO2 composites show an enhanced photocatalytic activity. Keywords: SnS2/TiO2; hierarchical macro/mesoporpous; photocatalytic; template-free

70

Wuhan, China

Poster Presentation PP4

Ionic liquid-facilitated synthesis and photocatalytic activity of TiO2/graphene composite hydrogel Ruirui Liu, and Zhijiang Ji * State Key Laboratory of Green Building Materials, China Building Materials Academy, Beijing 100024, PR China e-mail: [email protected]

Abstract: Graphene has been widely explored for applications in electronics, sensors, actuators,

catalysis and energy related systems.[1, 2] For these purposes, integration of individual twodimensional graphene nanosheets into three-dimensional monoliths through graphene gelation was developed to facilitate the formulation of high-performance graphene materials with a wide range of practical applications.[3] In the report, we have demonstrated a facile and efficient strategy for the fabrication of TiO2/graphene composite hydrogel using a ionic liquid-facilitated one-pot hydrothermal method. During the hydrothermal reaction, the graphene nanosheets and TiO2 nanoparticles self-assembled into three dimensional interconnected networks, in which the spherical nanostructured TiO2 nanoparticles with uniform size were densely anchored onto the graphene nanosheets. We have shown that the resultant TiO2/graphene composite hydrogel displayed the synergistic effects of the assembled graphene nanosheets and TiO2 nanoparticles and therefore exhibited a unique collection of physical and chemical properties such as increased specific surface area, improved adsorption capacities, and enhanced photocatalytic activities in comparison with pristine graphene and TiO2. As shown in Fig.1, Fig. 1A showed that the welldefined TiO2/graphene composite hydrogel was successfully prepared, In Fig. 1B, reflection peak of GO at around 2θ=10.8◦ disappeared in composite hydrogel, suggesting that the GO was fully reduced. The photocatlytic activity of TiO2/graphene composite hydrogel was estimated by photodegradation of methyl orange under UV light, and the results are shown in Fig. 1C. It is clear that methyl orange could be thoroughly degraded by the TiO2/graphene after less than 3 h. The synthesis method is efficient, scalable, green, and controllable and has the advantage of reduction of GO and formation of TiO2 occurring in one step. Therefore, this method can be readily extended to the preparation of other classes of hybrids based on graphene for technological applications.

Fig.1 (A) Gel macrographs of TiO2/graphene composite hydrogel, (B) XRD patterns of (a) GO (b) TiO2/graphene composite hydrogel, (C) photocatalytic degradation of methyl orange solutions (30 mg L-1) by TiO2/graphene with various graphene contents under UV-light irradiation. Keywords: TiO2/graphene • hydrogel • Ionic liquid • photocatalytic activity [1] M. J. Allen, V. C. Tung, R. B. Kaner, Chem. Rev., 2010, 110, 132-145. [2] R. A. Schäfer, D. Dasler, U. Mundloch, F. Hauke, A. Hirsch, J. Am. Chem. Soc., 2016, 138: 1647-1652. [3] Z. Niu, J. Chen, H. H. Hng, J. Ma, X. Chen, Adv. Mater., 2012, 24, 4144-4150.

71

Wuhan, China

Poster Presentation PP5

SiO2-VO2 composite membrane with Super hydrophobic and energy saving function Chao Wang1,2, Li Zhao1,2*, Zihui Liang1,2, Binghai Dong1,2, Zuxun Xu1,2, Li Wan1,2, Shimin Wang1,2 1 Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, 2 Key Laboratory for the Green Preparation and Application of Functional Materials, Ministry of Education, Faculty of Materials Science and Engineering, Hubei University, Wuhan 430062, PR China. *[email protected]

Abstract: Thermochromic Vanadium dioxide(VO2) has received great attention for smart window

application because of its well ability to control solar heat gain in response to the temperature variations. It goes through a first order reversible phase transition from the semiconductor to metallic state at critical temperature of 68℃, having higher infrared reflectance above this temperature[1]. Highly transparent, UV-regulating and super hydrophobic nanostructured SiO2-VO2 coating has been successfully fabricated by the sol-gel approaches. VO2 thin film was prepared by sol-gel technology at first and explored the thickness of the film which constrainly influence two factors: transmittance of visible light and amplitude of variation of transmittance in the rigion of the near infrared light[2]. With MTMS as silicon source precursor, vacuum drying and sol-gel method by changing the parameters such as methanol content, dry heat treat treatment temperature to explore suitable preparation conditions, in order to get into a good membranous, high porosity, good thermal conductivity and super hydrophobic performance of SiO 2 aerogel films[3,4]. Then SiO2 sol was spin coated on the VO2 thin film which has been prepared. After vacuum drying and annealing at high temperature. The VO2-SiO2 composite film with Super hydrophobic and energy saving function were prepared. Water droplets deposited on VO2-SiO2 coatings showing superhydrophobicity and high visible transmittance. The infrared region of the light transmittance regulating rang is about 24％at 2000 nm. Keywords: sol-gel method • phase transition • VO2-SiO2 composite films • Super hydrophobic [1]Seyfouri M M, Binions R. Sol-gel approaches to thermochromic vanadium dioxide coating for smart glazing application[J]. Solar Energy Materials and Solar Cells, 2017, 159: 52-65. [2]Liang Z, Zhao L, Meng W, et al. Tungsten-doped vanadium dioxide thin films as smart windows with self-cleaning and energysaving functions[J]. Journal of Alloys and Compounds, 2017, 694: 124-131. [3]Budunoglu H, Yildirim A, Guler M O, et al. Highly transparent, flexible, and thermally stable superhydrophobic ORMOSIL aerogel thin films[J]. ACS applied materials & interfaces, 2011, 3(2): 539-545. [4]Dhere S L, Latthe S S, Kappenstein C, et al. Transparent water repellent silica films by sol–gel process[J]. Applied Surface Science, 2010, 256(11): 3624-3629.

72

Wuhan, China

Poster Presentation PP6

Ni1-xFexOOH modified RGO/TiO2 for efficient photoelectrochemical water oxidation Xiaofan Zhang*, Weiqian Kong, Baocheng Yang Henan Provincial Key Laboratory of Nanocomposite and Applications, Institute of Nanostructured Functional Materials, Huanghe Science and Technology College, Zhengzhou, China e-mail: [email protected]

Current density / mA cm

-2

Abstract: The preparation of highly efficient and stable photoelectric catalysts and their interface reaction kinetics problems is one of the most popular research for hydrogen production with solar water splitting. Recently, many researchers have made focus on developing new co-catalyst1 or combining it with carbon nano-material2 to enhance the photoelectrochemical (PEC) performance for water oxidation. In our work, a new co-catalyst Ni1-xFexOOH was prepared via a modified electrochemical deposition method3 and then decorated the RGO/TiO2 nanorods. Because of the layered structure and special photocatalytic properties of RGO4, and the promoting the interfacial reaction of Ni1-xFexOOH5, the TiO2/RGO/Ni1-xFexOOH obtained the highest photocurrent density of 0.55 mA cm-2, which is 1.3 times higher than that of TiO2 NRs (0.4 mA cm-2) at 1.23 V vs. RHE. However, compared to the TiO2/RGO photoanode, the photocurrent density of TiO2/RGO/Ni1xFexOOH was nearly no change at 1.23 V vs. RHE. The onset potential of TiO 2/RGO/Ni1-xFexOOH negatively shifted 21 mV and 8 mV than that of TiO2NRs and TiO2/RGO. These results indicate that the co-catalyst Ni1-xFexOOH and RGO has a synergistic effect on improving the PEC performance. And the co-catalyst Ni1-xFexOOH plays a vital role in inhibiting the recombination of photo-generated carries and promoting the interfacial reaction. RGO mainly enhances the conductivity and improves the light absorption. This study will provide new ideas for designing and preparing the materials with high performance. 0.8 TiO2 NRs

0.6 0.4

TiO2 NRs/RGO TiO2 NRs/RGO/Ni1-xFexOOH

0.2 0.0 -0.2 -0.4 0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

Potential V / vs. RHE Firuge 1 The J-V curves under AM 1.5G simulated sunlight intermittently at a scan rate of 10 mV s -1 in 1 M NaOH for pristine TiO2, TiO2/RGO and TiO2/RGO/Ni1-xFexOOH electrodes.

Keywords: Co-catalyst• Ni1-xFexOOH• RGO• TiO2• Photoelectrochemical [1] [2] [3] [4] [5]

(a) W. Chen, T. Wang, J. Xue, S. Li, Z. Wang, S. Sun, Small, 2017, 1602420 (b) L. Cai, J. Zhao, H. Li, J. Park, I. Cho, H. Han, X. Zheng, ACS Energy Lett. 2016, 1, 624-632 (a) F. Ning, M. Shao, S. Xu, Y. Fu, R. Zhang, M. Wei, D. Evans, X. Duan, Energy Environ. Sci., 2016, 9(8): 2633-2643 (b) P. Zhang, T. Wang, X. Chang, L. Zhang, J. Gong, Angew.Chem. Int. Ed., 2016, 55, 5851-5855 (c) Y. Hou, Z. Wen, S. Cui, X. Feng, C. Chen, Nano Lett., 2016, 16 (4), 2268-2277 J. Deng, X. Lv, H. Zhang, B. Zhao, X. Sun, J. Zhong, Phys. Chem. Chem. Phys., 2016, 18(15): 10453-10458 (b) X. Li, J. Yu, S. Wageh, A. Al-Ghamdi, J. Xie, Small, 2016, DOI: 10.1002/smll.201600382 H. S. Ahn, A. J. Bard J. Am. Chem.Soc., 2015, 138(1): 313-318

73

Wuhan, China

Poster Presentation PP7

Metal-Organic Framework g-C3N4/MIL-53(Fe) Heterojunctions with Enhanced Photocatalytic Activity for Cr(VI) Reduction under Visible Light** Wenyuan Huang a, Ning Liu a, Yang Yang a, Xiaodong Zhang a,*, Minghong Wu b, Liang Tang b* Address: a School of Envir onment and Architecture, University of Shanghai for Science and technology, Shanghai 200093, China; b School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China e-mail: [email protected] (X.D. Zhang), [email protected] (L. Tang)

Abstract: The toxic heavy metal contamination in natural water has become one of the most serious environmental problems in the world. Hexavalent chromium (Cr(VI)) is a major pollution in the waste water arising from different industries, which can greatly threaten human health and contaminated environment. In contrast, Cr(III) plays an important role in human and plant metabolism. Therefore, reducing Cr(VI) to Cr(III) is an effective way to decrease the harm of Cr(VI) to the environment and human body[1]. Herein, we reported that the rational coupling of g-C3N4 and MIL-53(Fe) could favorably enhance activity for photocatalytic Cr(VI) reduction. A series of g-C3N4/MIL-53(Fe) nanocomposites were synthesized by a facile one-pot solvothermal reaction. The final products were labeled as CN/M53-3, CN/M53-5, and CN/M537(the numbers in the abbreviated name on behalf of the weight content of the CN for 3%，5%， 7%). To realize how the formation of the nanocomposite could prevent electron-hole recombination, it was important to determine the electronic configuration of the materials and particularly their band gaps and band edge energies. For this, UV-vis diffuse reflection spectroscopy (UV-vis DRS) and electrochemical impedance spectroscopy (Mott-Schottky approach) were used, respectively. MIL-53(Fe) strongly absorbed visible light (400-600 nm), as illustrated by its dark yellow sample color. The nanocomposites displayed a similar absorbance pattern to that of MIL-53(Fe). The absorption edge of CN/M53-3 blue shifted 30 nm compared to bulk MIL-53(Fe) due to the quantum confinement effect[2]. Photocatalytic reduction experiments of Cr(VI) over g-C3N4, MIL-53(Fe) and CN/M53-3, 5, 7 composites were performed under visible light irradiation (λ > 420 nm). As shown in Fig. 2, the CN/M53-3 composite shows the highest photocatalytic activity and 99% Cr(VI) is reduced after 180 min, which is almost 2.0 times and 1.5 times higher than that of pure g-C3N4 and MIL-53(Fe). (b) 1.0 Light on

0.8

C/C0

0.6

0.4

blank M53 g-C3N4

0.2

CN/M53-3 CN/M53-5 CN/M53-7

0.0 -40

-20

0

20

40

60

80

100

120

140

160

Time (min) Fig.1. Schematic illustration for the preparation (a) and photocatalytic activity of M53/CN hybrid composites (b)

Keywords:MIL-53(Fe) • g-C3N4 • Cr(VI) • visible light • photocatalysis [1] [2]

D. Xiao, K. Dai, Y. Qu, Y.P. Yin, H. Chen. Applied Surface Science, 2015, 358, 181-187. Hong J, Chen C, Bedoya F E, et al. Catalysis Science & Technology, 2016, 6, 5042-5051

74

180

Wuhan, China

Poster Presentation PP8

Effects of graphene doping amount on photocatalytic properties of MIL-88A(Fe)** Ning Liu a, Wenyuan Huang a, Pin Tao a, Xiaodong Zhang a, *, Liang Tang b, Minghong Wu b,* Address: a School of Envir onment and Architecture, University of Shanghai for Science and technology, Shanghai 200093, China; b School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China e-mail: [email protected] (X.D. Zhang), [email protected] (M.H. Wu)

Abstract: Recently, metal-organic frameworks (MOFs) have attracted tremendous attentions because of diverse structure features and desirable photocatalytic activity for eliminating environmental pollution. Among these MOFs, MIL-88A semiconductors have been extensively studied as a photocatalyst due to high stability, large and reversible swelling [1]. However, due to rapid recombination of photoexcited electron-hole pairs, the practical photocatalytic applications of MIL-88A are immensely limited. It has been reported that the photocatalytic applications of several GO-semiconductor (e.g., TiO2, ZnO, and Bi2 WO6 ) and those composites could favorably enhance the photoreactivity[2]. Thus, we try to research the effects of graphene loading on structure and photocatalytic properties of MIL-88A(Fe). It was found that GO/MIL-88A(Fe) displayed highly photocatalytic activity for the degradation of Rhodamine B (RhB) under visible light. A series of graphene/MIL-88A(Fe) nanocomposites were synthesized by a facile one-pot hydrothermal reaction. The final products were labeled as GO/M88A-1, GO/M88A-5, GO/M88A-9, and GO/M88A-11 (the numbers in the abbreviated name on behalf of the weight content of the GO for 1%, 5%，9%，11%). The absorbance properties of the as-prepared samples were measured using UV-vis diffuse reflection spectroscopy (UV-vis DRS). As shown in Fig. 1(a), after GO is wrapped on the surface of MIL-88A, the absorption of GO/M88A composites was enhanced, especially in the visible light zone. As expected, the optical properties of GO/M88A could contribute to possessing efficient photo reactivity at visible light region. The photocatalytic degradation of RhB was investigated over these fabricated catalysts under visible light irradiation (λ > 420 nm). From Fig. 1(b), in regards to the MIL-88A, the pollutant conversion was just about 46% after 80 min photocatalytic reaction time. Compared with other composites, GO/M88A-9 sample shows the highest photocatalytic activity, which is consistent with the results of UV-vis DRS. (b) 1.0

(a)

0.8

0.6

C/C0

Absorbance (a.u.)

M88A GO/M88A-1 GO/M88A-5 GO/M88A-9 GO/M88A-11

Light on

blank blank+H2O2

0.4

MIL-88A GO/M88A-1 GO/M88A-5 GO/M88A-9 GO/M88A-11

0.2

0.0 200

300

400

500

600

700

800

-60

-40

-20

Wavelength (nm)

0

20

Time (min)

Fig.1. UV-vis diffuse reflectance (UV-vis DRS) (a) and photocatalytic activity (b) of the samples

Keywords: MIL-88A(Fe) • graphene • Visible light • Rhodamine B • photocatalysis [1] [2]

W T Xu, L Ma, F Ke, et al. Dalton Transactions, 2013, 43(9), 59-59. C Zhang, L Ai, J Jiang. Industrial & Engineering Chemistry Research, 2015, 54(1), 153-163.

75

40

60

80

Wuhan, China

Poster Presentation PP9

The graphitic-C3N4 based composites: Synthesis and properties Jiali Lv, Jinfeng Zhang, and Kai Dai* Address: College of Physics and Electronic Information, Anhui Key Laboratory of Energetic Materials, Huaibei Normal University, Huaibei, 235000 P. R. China. e-mail: [email protected] (K. Dai)

Abstract: With its extraordinary properties as the chemical inertness, thermal stability, nontoxicity, high surface area and apparent energy band structure changes, graphitic carbon nitride (g-C3N4) could have promising application in many fields, especially in the area of photocatalyst1. However, ordinary g-C3N4 has poor quantum yield which is caused by the fast recombination of photoinduced charge carriers. So it is necessary to construct a g-C3N4 based composite system to improve the photoactivity and solve the practical applications problem2, 3. Our group has tried a series of composite photocatalysts based on g-C3N4 since 2014 and paid much attention to the strategies on how to increase the surface area of g-C3N4 and control the band gap match between g-C3N4 and other semiconductor to improve the photocatalytic performance. TiO24, graphene oxide5, Bi2MoO66, Ag2WO47, Ag3PO48 and BiOBr 9 have been composited with gC3N4 to obtain an increased photocatalytic activity. Take porous g-C3N4/BiOBr as an example (Figure 1), an optimal porous g-C3N4 content has been determined to be 20 wt%, corresponding to apparent pseudo-first-order rate constant kapp of 0.088 min-1, which is 3.7 times, 4.2 times and 7.3 times as high as that of porous g-C3N4, BiOBr and common g-C3N4, respectively. Furthermore, photocatalytic stability is also improved. We think this g-C3N4 based composite system photocatalyst may supply a new insight for various environmental applications.

Figure. 1 TEM images of g-C3N4, porous g-C3N4 and elemental mapping images of Bi, O, Br, C, N

Keywords: g-C3N4 •semiconductor • composites • photocatalysis • progress [1] X. Wang, K. Maeda, A. Thomas, K. Takanabe, G. Xin, J. M. Carlsson, K. Domen and M. Antonietti, Nat Mater, 2009, 8, 76-80. [2] S. Cao, J. Low, J. Yu and M. Jaroniec, Adv Mater, 2015, 27, 2150-2176. [3] Q. Xiang, J. Yu and M. Jaroniec, J. Phys. Chem. C, 2011, 115, 7355-7363. [4] K. Dai, L. Lu, C. Liang, Q. Liu and G. Zhu, Appl. Catal. B: Environ., 2014, 156-157, 331-340. [5] K. Dai, L. Lu, Q. Liu, G. Zhu, X. Wei, J. Bai, L. Xuan and H. Wang, Dalton Trans, 2014, 43, 6295-6299. [6] J. Lv, K. Dai, J. Zhang, L. Geng, C. Liang, Q. Liu, G. Zhu and C. Chen, Appl. Surf. Sci., 2015, 358, 377-384. [7] K. Dai, J. Lv, L. Lu, C. Liang, L. Geng and G. Zhu, Mater. Chem. Phys., 2016, 177, 529-537. [8] J. Zhang, J. Lv, K. Dai, Q. Liu, C. Liang and G. Zhu, Ceram. Int., 2017, 43, 1522–1529. [9] J. Lv, K. Dai, J. Zhang, Q. Liu, C. Liang and G. Zhu, Sep. Purif. Technol., 2017, 178, 6-17.

76

Wuhan, China

Poster Presentation PP10

Extending visible light absorption effectively with broad spectrum sensitizer for improvement of H2 evolution of in-situ Cu/g-C3N4 nanocomponent Piyong Zhang , Ting Song, Tingting Wang , Heping Zeng* School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou, 510641, P. R. China. Tel.: +86-20-87112631; Fax: +86-20-87112631; E-mail: [email protected];

Abstract: Photocatalyst with broad spectrum absorption has been expected for a long time due to utilization of more visible light. Herein, we develop an in-situ approach to specifically fabricate Cu nanoparticles onto exterior surface of g-C3N4 and then sensitization with Erythrosin B, to improve the photocatalytic H2 evolution of g-C3N4 and extend spectrum absorption. The photocatalytic H2 evolution rate was promoted evidently which is 26 times higher than pure g-C3N4, and photocatalytic ability is kept until 700 nm wavelength. The origin of the improved activity was attributed to in-situ Cu nanoparticles modification which acts as an electron reservoir and dye sensitization which could extend visible light absorption, thereby preventing charge recombination and enhancing visible light utilization efficiency. In addition, photocatalytic stability was investigated and no significant attention was detected after six recycles.

Scheme 1 Illustration of the synthesis and photocatalytic H2 evolution procedure for Cu/g-C3N4/ErB. Keywords: In-situ synthesis • Cu/g-C3N4 • Dye sensitization • Broad spectrum absorption [1] P.Zhang, T. Wang, H. Zeng, Appl. Surf. Sci. 2017, 391, 404-414. [2] J. Ran, J. Zhang, J. Yu, M. Jaroniec, S.Z. Qiao, Chem. Soc. Rev. 2014, 43, 7787-7812. [3] S. Cao, J. Low, J. Yu, M. Jaroniec, Adv. Mater. 2015, 27, 2150-2176.

77

Wuhan, China

Poster Presentation PP11

B doped C3N4 modified TiO2 nanorods for efficient photoelectrochemical water oxidation Weiqian Kong, Xiaofan Zhang*, Baocheng Yang, Shouren Zhang Henan Provincial Key Laboratory of Nanocomposite and Applications, Institute of Nanostructured Functional Materials, Huanghe Science and Technology College, Zhengzhou, China e-mail:[email protected]

Abstract: With the development of clean and renewable power sources, hydrogen energy has been attracted tremendous interests, especially by photoelectrochemical (PEC) water splitting technology.[1-3] Recently, metal-free and graphite-like carbon nitride (g-C3N4) attracted more attentions due to its low cost, good stability, inherent chemical properties, excellent optical and photocatalytic properties (2.7eV corresponding to 450 nm).[4,5] In our present work, B doped g-C3N4 (B-C3N4) was prepared with anneal method, and then coupled with TiO2 nanorods (NRs) to fabricate B-C3N4/TiO2NRs nanocomposites. The results of PEC performance indicated that the BC3N4/TiO2NRs displayed higher photocurrent density of 1.01 mA cm-2 (ERHE=1.23Vvs. RHE), which is proximity four times larger than that of pristine TiO2 at the same potential. The BC3N4/TiO2NRs had a cathodic shift of the onset potential form 400 mV vs. RHE to 200 mV vs. RHE. Besides, the stability of the TiO2/B-C3N4 photoanode was also good. Such significant enhanced PEC perfomance was attributed to the extended light absorption arising from B-C3N4 and the improved the recombination of photogenerated carries due to the appropriate band-gap position. This work can be used for the fabrication of novel phoelectrode, which have potential application in studying the photoelectochemical water oxidation with a doped semiconductor photoelectrode. Keywords: TiO2•B doping•g-C3N4•photoelectrochemical•water oxidation [1] [2] [3] [4] [5]

M. Gratzel, Nature, 2001, 414, 338-344 F. E. Osterloh, Chem. Soc. Rev., 2013, 42, 2294-2230 F. N. Ning, M. F. Shao, S. M. Xu, Y. Fu, R. K. Zhang, M. Wwi, D. G. Evans, X. Duan, Energy Environ. Sci., 2016, 9, 26332643 J. Liu, Y. Liu, N. Y. Liu, Y. Z. Han, X. Zhang, H. Huang, Y. Lifshitz, S.-T. Lee, J. Zhong, Z. H. Kang, Science, 2015, 347, 970-974 Y. Wang, X. Wang, M. Antonietti, Angew. Chem., Int. Ed., 2012, 51, 68-89

78

Wuhan, China

Poster Presentation PP12

Progressive design of plasmonic metal-semiconductor ensemble toward improved vis-NIR-driven solar-to-chemical conversion** Chuang Han, Quan Quan, and Yi-Jun Xu* Address: State Key Laboratory of Photocatalysis on Energy and Environment, College of Chemistry, Fuzhou University, Fuzhou, P. R. China e-mail: [email protected]

Abstract: In this work, we report a new design for the effective harvesting of vis-NIR (λ > 570 nm) light for photoreduction processes by designing plasmonic Au NRs and metal nanoparticles (M NPs, M = Au, Ag, or Pt) co-decorated 1D CdS nanowire (NWs) composites (Figure 1). We predominantly show that the finely progressive control of a series of microscopic factors, including interfacial interaction, morphology optimization, and cocatalyst strategy in such metalsemiconductor heterostructure ensemble, can result in the tunable and improved performance for vis-NIR-driven plasmonic photocatalysis.[1] In particular, the cooperative cascade synergy, afforded by the intimate integration of these metal nanostructures with 1D CdS NWs, is able to facilitate the extraction and spatially directional separation and migration of hot charge carriers from Au NRs to 1D CdS NWs to M NPs, and provide highly active sites on the surface of semiconductor. These synergistic effects result in the optimal photocatalytic activity toward reduction of nitroaromatics and water splitting to hydrogen. We anticipate that this work would inspire further rational design of plasmonic metal-semiconductor-based composite system for manipulating the directional flow of hot charge carrier and thus improving the overall efficacy of the broad-spectrum SPR-mediated photocatalysis in solar energy conversion.

Figure 1. The mechanism toward photoreduction processes over the M NPs-CdS-Au NRs composites under Vis-NIR (λ > 570 nm) light irradiation. Keywords: surface plasmon resonance • metal nanostructure • photocatalysis • hot electron • near-infrared light [1]

C. Han, Q. Quan, H. M. Chen, Y. Sun, Y.-J. Xu, small, 2017, DOI: 10.1002/smll.201602947.

79

Wuhan, China

Poster Presentation PP13

Facile Synthesis and Characterization of N-doped TiO2/C Nanocomposites with Enhanced Visible-light Photocatalytic Performance Tiekun Jia a, , Fang Fu a, Dongsheng Yu a, Jianliang Cao b, Guang Sun b a

School of Materials Science and Engineering, Luoyang Institute of Science and Technology, Luoyang, 471023, PR China; bCollege of Chemistry and Chemical Engineering, Henan Polytechnic University, Jiaozuo 430070, PR China e-mail: [email protected]

Abstract: Since Fujishima et al first reported the phenomenon of photocatalytic splitting water on

TiO2 electrodes under ultraviolet light irradiation in 1972 [1], photocatalysis has been widely investigated for their application in environmental pollution purification and solar energy conversion due to increasingly rapid consumption of fuel and release of hazardous pollutants. Nowadays, TiO2 is generally considered to be a reliable photocatalyst under UV light irradiation because of its good photocatalytic capability, chemical stability, non-toxicity and low cost [1-7]. However, pure TiO2 suffers from poor visible light photoactivity due to its wide bandgap and rapid recombination of photo-generated electron-hole pairs, which limits its practical applications remarkably. Therefore, designing reasonable approaches to narrow the band gap and restrain the recombination of photo-generated electron-hole pairs is significantly essential for achieving TiO2 based photocatalysts with high efficiency. In this work, N–doped TiO2 nanocrystals modified with carbon (denoted as N-doped TiO2/C) were successfully prepared via a simple and green route, using titanium tetrachloride, aqueous ammonia and urea as starting materials. The as–prepared photocatalysts were characterized by X– ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, field emission scanning electron microscopy (FESEM) equipped with an energy dispersion X–ray spectrometer (EDS), transmission electron microscopy (TEM), UV–vis diffuse reflection spectroscopy, photoluminescence spectroscopy (PL), and nitrogen adsorption–desorption isotherms. Raman spectral characterization combined with the results of XPS and HRTEM confirmed that N dopant ions were successfully doped into TiO2 lattice and carbon species were modified on the surface or between the nanoparticles to form N-doped TiO2/C nanocomposites. Compared with that of pure TiO2, the adsorption band edge of N-doped TiO2/C nanocomposites exhibited an obvious red–shift to visible light region, indicating that the bandgap of N-doped TiO2/C nanocomposites is narrowed and the visible light harvesting is significantly enhanced due to N doping and carbon modification. The photocatalytic performance of the as-prepared photocatalytsts was evaluated by the degradation of Rhodamine B (RhB) under visible light (λ>420 nm), and the results showed that the N–doped TiO2 nanocomposites exhibited much higher visible-light photocatalytic performance than pure TiO2 and N–doped TiO2, which was mainly attributed to the enhanced light harvesting, augmented catalytic active sites and efficient separation of photogenerated electron-hole pairs. Keywords: Nanocomposites; TiO2; N doping; Carbon modification; Photocatalytic performance [1] A. Fujishima and K. Honda, Nature, 1972, 238, 37-38. [2] Q. Xiang, J. Yu, M. Jaroniec, Chem. Commun. 2011, 47, 4532-4534. [3] J.X. Low, B. Cheng, J.G. Yu, Appl. Surf. Sci. 2017, 392, 658-686. [4] X.F. Zhu, B. Cheng, J.G. Yu, W.K. Ho, Appl. Surf. Sci. 2016, 364, 808-814. [5] Z.H. Fan, F.M. Meng, M. Zhang, Z.Y. Wu, Z.Q. Sun, A.X. Li, , Appl. Surf. Sci. 2015, 360, 298-305. [6] T. Yan, R. Yuan, W. Li, J. You, Appl. Catal. A: Gen. 2014, 478, 204-210. [7] Z.Y. Zheng, Z.F. Wang, L.Y. Xie, Z.B. Fang, W.H. Feng, M.L. Huang, P. Liu, Appl. Surf. Sci. 2017, 392, 658-686.

80

Wuhan, China

Poster Presentation PP14

Fabrication of Luminescent Graphitic C3N4 nanosheets (g-C3N4 NS) and reduced graphene oxide (rGO) Composite Structure towards efficient photocatalytic activity** Changchao Jia, Yumeng Liu, and Ping Yang* Address: School of Material Science and Engineering, University of Jinan, 250022, Jinan, P.R. China e-mail: E-mail: [email protected]

Abstract: Semiconductor photocatalysis has emerged as one of the most promising technologies for environmental remediation and solar energy conversion. The growing concerns about visible lightdriven photocatalysts have stimulated extensive studies. Graphitic C3N4 nanosheets (g-C3N4 NS) and reduced graphene oxide (rGO) composite structure has been successfully prepared for efficient visible photocatalysis. Firstly, thin g-C3N4 NS with bright blue photoluminescence were prepared through an acid and alkali corrosion and ultrasonic-assisted method. And then g-C3N4 NS/rGO sample which was prepared through a hydrothermal synthesis offered high separation and transfer efficiency of photogenerated carriers because of the thin g-C3N4 NS attached closely to the rGO. A g-C3N4 NS/rGO (3 : 2) composite exhibits efficient visible-light photocatalytic performance. It could be attributed to three factors as follows. First, the large coherent interface between g-C3N4 NS and rGO sheets can inhibit the recombination of photogenerated carriers. Second, layer-by-layer assembly structure improves visible-light absorption. Lastly, the rGO sheets provide a large number of electronic transport channels for photogenerated electrons, promoting the separation and transfer rates of electron–hole pairs.

Keywords: Graphitic C3N4 nanosheets • reduced graphene oxide • composite structure • hydrothermal synthesis • photocatalytic [1] [2]

Z. Zhang, D. Jiang, D. Li, M. He and M. Chen, Appl. Catal., B, 2016, 183, 113. D. Jiang, T. Wang, Q. Xu, D. Li, S. Meng and M. Chen, Appl.Catal., B, 2017, 201, 617.

81

Wuhan, China

Poster Presentation PP15

Hierarchical double-shelled zinc nickel oxide hollow spheres derived from metal-organic frameworks as efficient photocatalysts for the degradation of Rhodamine B Ying Zhang, Jiabin Zhou* School of Resources and Environmental Engineering, Wuhan University of Technology, 122 Luoshi Road, Wuhan 430070, China e-mail: [email protected]

Abstract: Metal-organic frameworks (MOFs) are important functional materials which can be used

as a sacrificial template in the synthesis of hollow metal oxides. In this study, zinc nickel bimetalorganic frameworks microspheres are successfully synthesized by a one-step solvothermal method. Furthermore, hierarchical double-shelled NiO/ZnO hollow spheres are obtained by calcination of the bimetallic organic frameworks in air. The as-prepared sample (NiO/ZnO) is characterized by Xray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) , fourier transform infrared spectra (FTIR), energy dispersive X-ray spectroscopy (EDX), Xray photoelectron spectroscopy (XPS) and N2 adsorption-desorption measurement. Meanwhile, the photocatalytic activity of the prepared sample for the degradation of rhodamine B (RhB) under UVvisible light irradiation is also investigated. It was found that NiO/ZnO microsphere comprise a core and a nanorods-assembled exterior shell with a unique hollow hierarchically porous structure. The photocatalytic results show that NiO/ZnO hollow spheres exhibit excellent catalytic activity for RhB degradation, causing complete decomposition of 200 mL of 10 g/L RhB under UV-visible light irradiation within 3 h. The improvement in photocatalytic performance is attributed to the hierarchically porous morphology and the strong double-shell binding interaction, which enhances adsorption of the dye molecules on the catalyst surface and facilitates the electron/hole transfer within the framework. This work provides a facile and effective approach for the fabrication of hierarchical mixed metal oxides with high photocatalytic activity, which can be potentially used in the environmental purification. Keywords: Metal-organic framework •Photocatalyst • Zinc nickel oxide• Rhodamine B [1] Hexiang Deng, et al. Science.,2010, 327, 846 [2] Lei Han, et al. Dalton Trans., 2016, 45,13311-13316 [3] M. S. Deenadayalan, et al. Inorg. Chem., 2016, 55, 5320-5327 [4] Patrick L. Feng, et.al. J. Am. Chem. Soc., 2010, 132, 15487-15489 [5] Feng Zou, et.al. Adv. Mater., 2014, 26, 6622-6628 [6] S. Girish Kumar, et al. RSC Adv., 2015, 5, 3306-3351 [7] Jian-Rong Li, et al. Chem. Rev., 2012, 112, 869-932 [8] S. Bordiga, et al. Chem. Commun., 2004, 2300-2301 [9] Maryam Rad, et al. RSC Adv., 2016, 6, 61784-61793

82

Wuhan, China

Poster Presentation PP16

Gold nanoparticle modified graphitic carbon nitride films with enhanced photoelectrochemical performance Xiaowei Lv, Lei Pan, and Yan Shen* Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China e-mail: [email protected]

Abstract: Graphitic carbon nitride (g-CN) is a promising material for photoelectrochemical (PEC) water splitting because its appropriate band gap, excellent thermostability, nontoxicity, easily obtained raw material and low cost. [1, 2] Nevertheless, the application in PEC system is limted by insufficient light absorption, poor electric conductivity and serious photocorrosion. [1,3] Here, we report a thermal vapor condensation combined with photodeposition method to prepare gold nanoparticle modified g-CN films on FTO substrate. The photocurrent of the resulting films is about twofold higher than pristine g-CN films at the bias of 1.23 V versus reversible hydrogen electrode in 0.1M KOH electrolyte. The result ascribes to improved charge transfer resistance. This method can be expanded to the preparation of g-CN based composite by instead of gold with other precious metal materials for enhancing PEC water splitting.

Keywords: graphitic carbon nitride• gold • photoelectrochemical • water splitting [1] [2] [3]

J. Bian, Q. Li, C. Huang, J. Li, Y. Guo, M. Zaw, R.-Q. Zhang, Nano Energy, 2015, 15, 353-361. X. Wang, K. Maeda, A. Thomas, K. Takanabe, G. Xin, J.M. Carlsson, K. Domen, M. Antonietti, Nat. Mater., 2009, 8,76-80. Xu J, Cao S, Thomas B, et al. Adv. Funct.Mater., 2015, 25, 6265-6271.

83

Wuhan, China

Poster Presentation PP17

A Robust Self-Sacrificial Strategy to Construct g-C3N4/LaCO3OH Heterostructures with High Photocatalytic NOx Removal Efficiency Zhenyu Wang, Yu Huang *, Junji Cao Key Lab of Aerosol Chemistry & Physics, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an 710061, China State Key Lab of Loess and Quaternary Geology (SKLLQG), Institute of Earth Environment, Chinese Academy of Sciences, Xi’an 710061, China e-mail: [email protected]

Abstract: Secondary aerosols, which are formed from the photochemical reactions with NOx as one of the key precursors, contributed 30~77% of PM2.5 mass concentrations during haze episode [1]. Thus it is essential to develop efficient method to mitigate NOx in view of effective air pollution control. Photocatalysis as a mild advanced oxidation technology can utilize natural sunlight to purify air pollutants at ambient conditions, and is regarded as a promising route for atmospheric NOx control[2]. In contrast to single semiconductors, heterostructure composites can effectively restrain the recombination of photoinduced e−-h+ pairs [3]. In this study, a novel LaCO3OH (LCOH) hierarchical reuleaux triangle nanostructure was fabricated firstly via a one-pot hydrothermal strategy, relying on the dual-function roles of g-C3N4 (CN), namely as a CO32− provider and also as a structure-directing agent. The experimental results showed that the in situ fabricated g-C3N4/LaCO3OH (CN-LCOH) heterojunction exhibited enhanced visible-light-driven photocatalytic activity for NO removal (30.3%) than that of mechanically mixed sample (Fig. 1a), which can be ascribed to the intimate interfacial contact. Results from photocurrent tests demonstrated that the g-C3N4/LaCO3OH sample presents much more effective interface charge separation efficiency (Fig. 1b). More importantly, this novel synthesis strategy was successfully extended to synthesize g-C3N4/Bi2O2CO3 and g-C3N4/SrCO3 composites. (b) (a)

Fig. 1 Visible light photocatalytic activities for NO removal in air (a) and photocurrent transient under visible light irradiation (λ > 420 nm) Keywords: Heterojunction, g-C3N4/LaCO3OH, Self-sacrificial synthesis, NO photocatalytic oxidation [1] [2] [3]

Huang, R. J.; Zhang, Y.; Bozzetti, C.; Ho, K. F.; Cao, J. J.; Han, Y.; Daellenbach, K. R.; Slowik, J. G.; Platt, S. M.; Canonaco, F., Nature, 2014, 514, 218-22 Huang, Y.; Ho, W.; Lee, S.; Zhang, L.; Li, G.; Yu, J. C., Langmuir 2008, 24, 3510-6 J. Shi, Chem. Rev., 2012, 113, 2139-2181

84

Wuhan, China

Poster Presentation PP18

Chemical etching fabrication of mesoporous Bi2O3@Bi nanospheres with high visible-light-activity Peng Zhang, Yu Huang*, Junji Cao* Institute of Earth Environment,Chinese Academy of Sciences, Xi’an, 710061,China *e-mail: [email protected]

Abstract: Elemental Bi is a typical group V semimetal material and has interesting photoelectric properties such as small band gap, small effective mass, low carrier density, high carrier mobility and extremely long carrier mean free path. To enhance the special photocatalytic properities and potential applications, different morphologies and structures Bi nanomaterials were prepared[1-3]. More recently, some novel morphologies of Bi photocatalysts, including nanoparticles[4, 5], nanospheres[1, 6, 7] and nanobundles[8] have been reported and appeared good photocatalytic properties under UV-light and visible-light irradiation. Mesoporous Bi2O3@Bi nanospheres was fabricated via a special chemical etching method for the first time and a certain concentration of HCl-EtOH solution as etching agent. The typical of mesoporous structure was achieved and the pore size was uniform with the mean value of 3.5 nm. Moreover, The visible light absorption was good and the optical band gap was 0.7 eV. The results indicated that the Mesoporous Bi2O3@Bi nanospheres exhibited good light absorption property, The degradation efficiency was about 3 times that of the sample without etching for degradation of NO under visible light irradiation.

Keywords: Chemical etching, Bi2O3@Bi, Mesoporous structure, photocatalytic [1]. [2]. [3]. [4]. [5]. [6]. [7]. [8].

Z. Cui, Y. Zhang, S. Li, S. Ge, Catalysis Communications. 72 (2015) 97-100. D. Ma, J. Zhao, Y. Zhao, X. Hao, Y. Lu, Chemical Engineering Journal. 209 (2012) 273-9. F. Dong, T. Xiong, Y. Sun, Z. Zhao, Y. Zhou, X. Feng, Z. Wu, Chemical communications. 50 (2014) 10386-10389. J. Toudert, R. Serna, M. Jiménez De Castro, The Journal of Physical Chemistry C. 116 (2012) 20530-20539. F. Dong, Z.W. Zhao, Y.J. Sun, Y. X. Zhang, S.Y, Z.B. Wu, Environmental Science Technology. 49 (2015) 12432-12440. Z. Wang, C. Jiang, R. Huang, H. Peng, X. Tang, The Journal of Physical Chemistry C. 118 (2014) 1155-1160. D.C. Ma, Y. Zhao, J.Z. Zhao, Y.W. Li, Y. Lu, D.J. Zhao, Superlattices and Microstructures. 83 (2015) 411-421. Y. Huang, W. Wang, Q. Zhang, J.J. Cao, R.J. Huang, W. Ho, S.C. Lee, Scientific reports. 6 (2016) 23435.

85

Wuhan, China

Poster Presentation PP19

Preparation of g-C3N4 based semiconductor composites with highlyefficient photocatalytic activity** Yanbiao Shi, and Qizhao Wang* College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, China E-mail: [email protected]

Abstract: Developing low-cost and efficient semiconductor photocatalysts has been regarded as a reliable and effective approach to resolve the increasingly serious energy crisis and environmental pollution. Graphitic carbon nitride (g-C3N4), a layered structure with weak van der Waals forces between layers, has been widely used in photocatalysis field due to the easy synthesis, narrow bandgap and excellently visible-light-response activity. But the rapid recombination rate of photoinduced carriers and limited reactive sites is infaust to fully utilize it as an efficiently visible-lightdriven material. There are several methods to dissolve the mentioned questions: combining with other semiconductor materials to form composites for speeding the separation and transfer of electron-hole pairs; treating under inert gases atmosphere to break the hydrogen bonds in the intralayer framework for forming abundant pores with shorter diffusion lengths of electrons from the particle interior to the lateral edges; preprocessing in organic solvents under hydrothermal conditions to achieve carbon atom self-doping g-C3N4 for increasing reactive center. Thus, several composites with high-activity have been synthesized. Rod-like g-C3N4/ZnS composites show superior performance for pollutant elimination under visible light irradiation due to the expanded photo absorption edge. C atom self-doping g-C3N4/CuS visible-light-driven composites can effectively degrade several commonly dyes owing to the enlarged specific surface area and enhanced charge separation and transfer efficiency. Meanwhile, the variety of g-C3N4 addition content could control the valence change of Cu element in CuOx composites to form CuO and Cu2O. Besides, coupling quantum dots (eg: C QDs, CdS QDs, ZnS QDs et al.) with g-C3N4, hydrogen bonds in intralayer broken selectively, could increase the H2 production from water splitting and improve the quantum efficiency under visible light irradiation, which may be ascribed to more low-energy photons excited and higher separation efficiency of carriers for shallow charge trapping states introduced. Hence, modulating bulk g-C3N4 in molecular level is an alternative pathway to achieve solar energy utilization. Acknowledgements:This work was financially supported by the National Natural Science Foundation of China (21663027, 51262028) and the Program for the Young Innovative Talents of Longyuan. Keywords: g-C3N4 • photocatalytic • quantum dot • hydrogen evolution • organic degradation [1] J. Liu, Y. Liu, N. Liu, Y. Han, X. Zhang, H. Huang, Y. Lifshitz, S. Lee, J. Zhong, Z. Kang, Science, 2015, 347, 6225. [2] Y. Kang, Y. Yang, L. Yin, X. Kang, L. Wang, G.Liu, H. Cheng, Adv. Mater. 2016, 28, 6471-6477. [3] X. Zhang, H. Wang, H. Wang, Q. Zhang, J. Xie, Y. Tian, J. Wang, Y. Xie, Adv. Mater. 2014, 26, 4438–4443. [4] Y. Kang, Y. Yang, L. Yin, X. Kang, G.Liu, H. Cheng, Adv. Mater. 2015, 27, 4572-4577.

86

Wuhan, China

Poster Presentation PP20

The study of ZnO samples synthesized via simple solvothermal method and photocatalytic properties** Yu Liu, Haixia Liu* Address: Shandong Provincial Key Laboratory of Fine Chemicals, School of Chemistry and Pharmaceutical Engineering, Qilu University of Technology, Jinan, China. e-mail: [email protected]

Abstract: ZnO is a major area of interest within the field of semiconductor science because of

excellent physical and chemical properties. In this work, we successfully synthesized ZnO nanomaterials with different morphologies and colours via simple solvothermal method. We selected urea as adjuvant in the growth process of ZnO crystalline. The colour of as-prepared ZnO samples exhibited interesting variation with the amount of urea changed. We used XRD, SEM, UVvis and PL spectrum to characterized ZnO samples. The SEM images of as-prepared ZnO particles changed obviously with different value of urea. The growth mechanism was studied according to crystalline theoretical knowledge. And the UV-vis spectrum and PL spectrum showed that the asprepared ZnO samples with certain amount of urea have obvious absorption in the visible region. This is different from other reported ZnO samples. We think that there is auto-doped pattern in the growth process of ZnO crystals with the assistance of urea. So, we tested the photocatalytic properties of ZnO samples under the visible light irradiation. What’s more, we also intend to explore the application in photocatalytically splitting of water.

Fig. 1 The different colour of ZnO synthesized with urea .

Fig.2 The SEM images of as-prepared ZnO samples.

Fig. 3 The UV-vis and PL spectrum of ZnO samples. Keywords: ZnO nanomaterials • photocatalytic property [1] [2] [3] [4]

Y. S. Liu, W. W. Chen, S. H. Wei, W. Gao, RSC Adv., 2014, 4, 30658-30665. R. Jacobs, B. Zheng, B. Puchala, J. Phys. Chem. Lett, 2016, 7, 4483-4487. J. Liu, Z. Y. Hu, Y. Peng, H. W. Huang, Y. Li, M. Wu, X. X. Ke, Appl. Catal. B-Environ, 2016, 181, 138-145. J. Chang, R. Ahmend, H. X. Wang, H. W. Liu, R. Z. Li, P. Wang, J. Phys. Chem. C, 2013, 117, 13836-13844.

87

Wuhan, China

Poster Presentation PP21

Synthesis and photocatalytic activity of flower-like anatase TiO2 with nanosheets** Kerui Fan, Haixia Liu** Address: Shandong Provincial Key Laboratory of Fine Chemicals, School of Chemistry and Pharmaceutical Engineering, Qilu University of Technology, Jinan, China. e-mail: [email protected]

Abstract: Flower-like TiO2 with high specific surface area are specially significant in various applications. In this work, we successfully synthesized TiO2 by one-pot solvothermal method. We study the growth mechanism by controlled reaction time, it shows that the nanosheets were more various with time prolonged. The morphology and microstructure were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and Brunauer-Emmett-Teller N2 gas adsorption-desorption isotherm. The results showed that the flower-like TiO2 nanostructure has large surface area and exhibited best crystallinity. We study its photocatalytic activity by degradation of methylene blue, we find that the anatase TiO2 with flowerlike exhibited high photoactivity.

Fig.1 The SEM images of as-prepared TiO2 samples.(a 1h,b 2h,c 6h, d 10h)

Fig.2 The BET surface area images of as-prepared TiO2 samples.(1-1h,2-2h,3-6h, 4-10h) Keywords: flower-like TiO2 ·photocatalytic activity [1] [2]

J.G. Yu, Q.J. Xiang, J.R. Ran, S. Mann, Cryst. Eng. Comm. 2010, 12, 872–879. H.Y. Yin, X.L. Wang, L. Wang, Q.L. N, H.T. Zhao, J. Alloys Comp. 2015, 640, 68-74

88

Wuhan, China

Poster Presentation PP22

In situ prepared Au nanoparticles on ZnO/g-C3N4 nanocomposites as plasmonic photocatalysts for significantly enhanced hydrogen production** Jian Zeng a,c, and Heping Zeng a,b* Address: a Guangzhou Key Laboratory of Materials for Energy Conversion and Storage, School of Chemistry and Environment, South China Normal University, Guangzhou, 510006,P.R.China b Key Laboratory of Functional Molecular Engineering of Guangdong Province, School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou, 510640, P.R.China Department of Chemistry, National University of Singapore, 3 Science Drive 3,117543, Singapore e-mail: [email protected]

SPR

+ +

+ ++

_

-1.5 -1.0 -0.5 0.0 0.5 1.0 1.5 2.0 2.5 3.0

-1.25 eV

_

e- CB

_ _

e-

-0.54 eV

_

+

_ _

+

_ _ __ _

+

+ + ++

CB

EF Ef

+ e- e SPR 2H state eEf H2 Au H+/H =0 V 2

g-C3N4 TEA 1.49 eV TEA+

2.48 eV

light h+

VB

light h+ ZnO VB

Hydrogen evolution rate / (mol/g•h)

Abstract: Hydrogen is considered as a potential fuel to address the energy and environmental issue nowadays. The photocatalytic hydrogen production from water plays an important role in hydrogen generation methods for the carbon-based system transition to hydrogen-based energy system [1-2]. Nevertheless, there exist many challenges to find suitable photocatalysts that use sunlight effectively. Efficient charge separation plays an important role in solar-energy conversion by heterojunction photocatalysts [3-5]. Therefore, in this work, Au/ZnO/g-C3N4 plasmonic photocatalysts were successfully prepared, characterized and evaluated photoactivity for hydrogen production under simulated sunlight irradiation for the first time. The results indicated that g-C3N4 was closely coupled with ZnO, and AuNPs was successfully loaded on the surface of ZnO/g-C3N4 sandwich nanocomposite. Subsequently, the photoactivity for hydrogen generation of assynthesized sample was investigated and optimized. The results suggested that the photoactivity of Au/ZnO/g-C3N4 plasmonic photocatalysts was significantly enhanced via the localized SPR effect, and the optimal Au/ZnO/g-C3N4 nanocomposite with Au loading 0.7 wt % exhibits the hydrogen generation rate of 889 µmol·g-1·h-1, which was more than 12 times and 8 times, respectively, relative to the values of pure ZnO and g-C3N4, whereas the optimized ZnO/g-C3N4 nanocomposite with ZnO coupling 5.8 % shows the hydrogen generation rate of 544 µmol·g -1·h-1. Additionally, the mechanism of the ternary hybrid plasmonic photocatalysts for enhanced photoactivity was also tentatively proposed.

TEA TEA+

900 800 700 600 500 400 300 200 100 0

pure ZnO pure g-C3N4

889

8ZCN 0.7 wt% Au/8ZCN 544

69

101

Photocatalysts Fig.1 Proposed mechanisms for the charge carrier transfer process in the Au/ZnO/g-C3N4 photocatalysts and the hydrogen production rate of representative photocatalysts.

Keywords: Plasmonic • Au/ZnO/g-C3N4 • Photocatalytic• Hydrogen generation • Mechanism [1] [2] [3] [4] [5]

J. Liu, Y. Liu, N. Y. Liu, Y.Z. Han, X. Zhang, H. Huang, Y. Lifshitz, S. T. Lee, J. Zhong and Z. H. Kang, Science, 2015, 347, 970-974. J. Zeng, T. Song, M. X. Lv, J. Y. Qin, T. T. Wang, H. P. Zeng, RSC Advances, 2016, 6, 54964-54975. J. P. Huo, H.P. Zeng, J. Mater. Chem. A, 2015, 3, 17201-17208. J. P. Huo, H.P. Zeng, Appl. Catal. B: Environ., 2016, 199, 342-349. P. Y. Zhang, T. Song, T. T. Wang, Appl. Catal. B: Environ., 2017, 206, 328-335.

89

Wuhan, China

Poster Presentation PP23

Fabrication of three dimensional CNT-graphene/BiOI nanostructure electrode in photoactivated fuel cell to recover energy from organic pollutants Lingling Hu a, Chun He a,b*, Jiawei Zeng a, Yajing Huang a, Wenjun Xua, Zhuoyan He a, Xiuqin Tan a

b

a School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Guangzhou, 510275, China *[email protected]

Abstract: Environmental pollution and energy crisis are two critical addressing problems to our

society [1]. Alternative, photoactivated fuel cell (PFC) is an ideal clean energy device for solving the problems simultaneously [2]. A visible-light-driven PFC system, consisting of a three dimensional CNT-graphene/BiOI photoanode and a Pt photocathode, was used to recover energy by using wastewater organic compounds as electrolyte and fuel. The nanostructured CNTgraphene/BiOI composites were prepared by one-step hydrothermal method. The prepared CNTgraphene/BiOI photoanode were characterized by X-ray diffraction (XRD), scanning electronic microscope (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and UV-Vis diffuse reflectance spectroscopy (DRS) to examine the surface structure and the properties of light absorption. The photoactivity of CNT-graphene/BiOI photoanode was evaluated in the term of the electricity generation efficiency and degradation efficiency for organic pollutants. The electricity generation of CNT-graphene/BiOI based PFC system was optimized through investigated the influence of different experiment conditions. Under optimal conditions, CNTgraphene/BiOI photoanode demonstrated a much better efficiency of electricity generation and degradation for organic pollutants in PFC system under visible light, compared with BiOI, Gr/BiOI, CNT/BiOI photoanodes. The enhancement in the efficiency of electricity generation and degradation for organic pollutants was ascribed to a synergistic effect between BiOI and CNTgraphene hybrid. When CNT-graphene hybrid was introduced, CNT-Gr/BiOI exhibited an obvious enhancement in visible light absorption and can provide more active sites for organic pollutants oxidation with increased specific surface area. Moreover, a facile electron pathway was realized due to the good conductivity of CNT-graphene hybrid. Keyword: Plasmonic • Au/ZnO/g-C3N4 • Photocatalytic• Hydrogen generation • Mechanism [1] H. Cai, P.P. Liang, Z.G. Hu, L.Q. Shi, X. Yang, J. Sun, N. Xu and J.D. Wu. Nanoscale, 2016, 11, 1-11 [2] K. Li, H.B. Zhang, Y.P. Tang, D.W. Ying, Y.L. Xu, Y.L. Xu, Y.L. Wang, J.P. Jia. Appl. Catal. B, 2015, 164, 82-91

90

Wuhan, China

Poster Presentation PP24

Highly efficient photocatalytic hydrogen generation on CdS using graphene and MoS2 nanosheets as cocatalysts Liwen He, Bolin Zhu, Yan Liu, Peipei Liu, and Bizhou Lin* College of Materials Science and Engineering, Huaqiao University, Xiamen 361021, China e-mail: [email protected]

Abstract: Graphene possesses an extremely high specific surface area and an excellent electron transport property. Numerous efforts have been made to combine graphene with semiconductors for improving their photocatalytic performance [1]. CdS has a relatively narrow bandgap, endowing CdS to have a high photoactivity for H2 evolution from water under visible-light irradiation. On the other hand, MoS2 has been proven as a promising cocatalyst for H2 evolution [2]. It is known that individual single-layer MoS2 nanosheets can be achieved through exfoliating natural molybdenite [3]. Herein we report for the first time the preparation of CdS nanoparticles through a simple onepot hydrothermal method in the presence of graphene and MoS2 nanosheets.

Fig. 1 Typical TEM (A and B) and HRTEM images (C) of CdS/graphene/MoS 2.

300

GO

100

MoS2

200

CGM2.0

CGM0.5

400

CGM1.5

CGM1.0

500

CdS

Rate of H2 production / mol.h-1.g-1

As shown in Fig. 1, graphene functions as the supported platform for the deposition of exfoliated MoS2 nanosheets and the growth of the CdS nanoparticles with an intimate interfacial contact. The intimate contact is expected to form a desirable heterostructure, which was supported by XPS, Raman, UV-vis DRS and photocurrent responses. Due to the synergistic effect between the components, the resultant CdS/graphene/MoS2 nanocomposites exhibited significantly enhanced photocatalytic activities and good stability in H2 evolution from water splitting under visible-light irradiation.

0

Different samples

Fig. 2 Comparison of H2-production rates on different catalysts under the employed conditions of 100 mg catalyst, 100 mL aqueous solution containing 0.005 M Na2S and 0.005 M Na2SO3, and 300 W Xenon lamp irradiation with a 420 nm filter, where x in CGMx is weight percent of MoS2 in CdS/graphene/MoS2 nanocomposites.

Keywords: Graphene • Molybdenum disulfide • Cadmium sulfide • H2 production • Phototcatalysis [1] [2] [3]

Q.J. Xiang, J.G. Yu, M. Jaroniec, Chem. Soc. Rev., 2012, 41, 782–796 B. Zhu, B. Lin, Y. Zhou, P. Sun, Q. Yao, Y. Chen, B. Gao, J. Mater. Chem. A, 2014, 2, 3819–3827 V. Nicolosi, M. Chhowalla, M. G. Kanatzidis, M. S. Strano, J. N. Coleman, Science, 2013, 340, 1226419.

91

Wuhan, China

Poster Presentation PP25

Molybdenum phosphide modified carbon nitride as an efficient photocatalyst for hydrogen generation Zhen Peng, Wei Liu, Yanhui Fu, Shufang Chang, Hua Tang School of Materials Science and Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013, People’s Republic of China.

Abstract: Integration of g-C3N4 into photocatalytic splitting water has been of great interest, as it may extend the spectral range of light absorption towards visible light spectrum.Here we develope a facile synthesis approach to integrate molybdenum phosphide(MoP) to g-C3N4 as a photocatalyst for the highly efficient hydrogen generation by water splitting under visible light irradiation. The remarkably improved photocatalytic activities of MoP/g-C3N4 can be attributed to the cooperative work of MoP nanoparticles and g-C3N4, which facilitate the separation of photo-generated carriers and suppress the recombination of the electron-hole pairs. Our studies may open a new window to design economical noble-metal-free catalysts for efficient solar energy conversion. Keywords: Molybdenum phosphide，Photocatalytic，C3N4，hydrogen generation

92

Wuhan, China

Poster Presentation PP26

Designing metal-free, robust, and regenerable 3D graphene-organics aerogels with high and stable photosensitization efficiency** Min-Quan Yang, and Yi-Jun Xu* Address: State Key Laboratory of Photocatalysis on Energy and Environment, College of Chemistry, Fuzhou University, Fuzhou, P.R. China e-mail: [email protected]

Abstract: The design of efficient visible-light-driven photocatalysts that comprise low-cost and earth-abundant materials with easy recyclability is a significant and enduring theme for solar energy conversion toward practical applications. [1-3] Herein, we report a facile and generalized one-step hydrothermal method for the synthesis of metal-free 3D macroscopic graphene-organics aerogels in which the organic dyes as photosensitizer are spatially confined and distributed in the graphene framework. This 3D bulk aerogel with interconnected conductive porous structure displays fast spatial separation and transportation of photogenerated charge carriers, high adsorptivity of target reactants, as well as easy separability and recyclability from the reaction medium. In particular, such a bulk aerogel manifests excellent regenerability via a simple replenishment of fresh dyes, which guarantees the long-term photocatalytic performance of the 3D aerogel. Consequently, the as-synthesized mechanically robust aerogel photocatalysts demonstrate high visible-light-driven (λ > 420 nm) activity and stability toward photoreduction of nitro compounds and Cr (VI). This universal approach for fabricating 3D graphene-organics aerogels is expected to open a new vista for constructing a new type of metal-free and robust visible-light photocatalysts for artificial photoredox, as well as offering a generic way to improve the photosensitization efficiency of traditional organic dyes.

Figure 1. Schematic illustration of visible-light-driven (λ > 420 nm) photocatalytic reduction of nitro compounds and reduction of Cr(VI) over 3D graphene-EY aerogel photocatalysts. Note: O and O*in (G) represent the ground state and excitation state of organic dye, respectively. Keywords: graphene-organics • metal-free aerogel • photosensitization efficiency • long-term stability • regenerability [1] [2] [3]

N. Zhang, M.-Q. Yang, S. Liu, Y. Sun, Y.-J. Xu, Chem. Rev., 2015, 115, 10307-10377 M.-Q. Yang, N. Zhang, M. Pagliaro, Y.-J. Xu, Chem. Soc. Rev., 2014, 43, 8240-8254 M.-Q. Yang, N. Zhang, Y. Wang, Y.-J. Xu, J. Catal., 2017, 346, 21-29

93

Wuhan, China

Poster Presentation PP27

The effect of the calcination temperature to the visible light photocatalytic activity of direct contact Z-scheme g-C3N4-TiO2 Juan Li a,b,c, Min Zhang a,b, Xuan Li a,b, Qiuye Li a,b, Jianjun Yang a,b* a

National & Local Joint Engineering Research Center for Applied Technology of Hybrid Nanomaterials, Henan University, Kaifeng, 475004, China. b Collaborative Innovation Center of Nano Functional Materials and Applications of Henan Province, Henan University, Kaifeng, 475004, China. c Henan Engineering Research Center of Resource & Energy Recovery from Waste, Henan University, Kaifeng, 475004, China. * Corresponding author, E-mail: [email protected].

1. Introduction: In order to improve the intrinsic imperfection of wide bandgap and high recombination rate of photoinduced electrons-holes [1] for the wellknown photocatalytic materials TiO2, coupling with narrow bandgap semiconductors such as graphite-phase carbon nitride (g-C3N4) [2-4] is a good method to solve this problem, and many researchs have obtained the remarkable effect [5,6] . However, there was little research about the influence of the g-C3N4 structure in the composites to the photocatalysis. In this work, g-C3N4 was selected to modifying the novel-TiO2 which had a certain visible light absorption with large amounts of single-electron-trapped oxygen vacancy (SETOVs, denoted as V0 •) at different calcination temperature and discussed the influence of the annealing temperature to the band structure, the thickness of g-C3N4 nanosheets, optical absorption and charge carriers transport performance of the nanocomposites in detail. 2. Experimental: NTA was prepared by the hydrothermal treatment of the concentrated alkaline and P25 powder according to our previously reported method [7]. The bulk g-C3N4 was prepared by heating melamine at 550 ℃ for 2 h in a furnace. A certain amount of bulk g-C3N4 and NTA powder were ground for 30 min thoroughly, then the mixture was transferred into a porcelain boat and heated from room temperature to the designated temperature for 2 h in a tubular furnace, under air atmosphere at a heating rate of 5 ℃·min-1. Finally, a series of different temperatures composites of x%g-C3N4-TiO2-y (x denoted the mass percentage of g-C3N4 in the mixture of bulk g-C3N4 and NTA and y represented the calcination temperature) were obtained. 3. Results and discussion: As shown from Figure 1A, we prepared a series of 20%g-C3N4-TiO2 composites from 300 to 700 oC to investigate the influence of the annealing temperature to the composites photocatalytic activity and the samples activity presented the trend of upgrade firstly and then descending. Especially, the sample of 600 oC had the best activity while the sample of 400 and 500 oC had almost the same activity. The reason was that g-C3N4 was very stable below 600 oC but it would partially decompose to form thin g-C3N4 nanosheets in air at 600 oC according to our preceding research [7]. When the temperature increasing to 700 oC the g-C3N4 decomposed compeletely and so the sample of 700 oC had very poor photoactivity. We selected the optimum g-C3N4 content photocatalytic oxidation propylene samples at 400 and 600 oC respectively to investigate the reason for the vast activity difference (seen in Fig. 1B). The results of Fig. 1C and 1D indicated that 30%g-C3N4-TiO2-600 and 20%g-C3N4-TiO2-400 samples were both direct contact Z-scheme heterojunction but 30%g-C3N4-TiO2-600 had the stronger generating •OH radicals ability and the higher separation efficiency of the photogenerated electrons-holes. The reason was that only the sample of 600 oC presented polyporous construction arising from the decomposition of g-C3N4 [7] which facilitated the transport of carriers and reaction products (seen in Fig. 1E).

94

Wuhan, China

Fig. 1. The propylene oxidation activity changed with different annealing temperature in the 20%g-C3N4-TiO2 samples (A) and the best g-C3N4 content samples at 400℃ or 600℃, bulk and g-C3N4 nanosheets (B) under visible light (λ≥ 420 nm) illumination; (C) The samples of PL intensity@425nm in 2×10-3 M NaOH solution with presence of 5×10-4 M terephthalic acid under visible light (λ≥ 420 nm), and the photocatalytic mechanism diagram (E) of the 400 and 600 composites.

4. Conclusions: A series of g-C3N4-TiO2 direct contact Z-scheme heterojunction nanocomposites were prepared via simple calcination of NTA and g-C3N4 at different temperatures and the sample of 600 oC had the best photocatalytic oxidation activity of propylene under visible light. This can be attributed to the polyporous construction in g-C3N4 nanosheets arising from the decomposition of gC3N4 which facilitated the better charge transfer and separation efficiency between g-C3N4 nanosheets and novel TiO2 of the direct Z-scheme heterojunction effect. Keywords: calcination temperature • g-C3N4 nanosheets • Z-scheme • photo-oxidation of propylene [1] M. R. Hoffmann, S.T. Martin, W. Choi, D.W. Bahnemann, Chem. Rev. 95 (1995) 69-96. [2] Y. Li, H. Zhang, P. Liu, D. Wang, Y. Li, H. Zhao, Small 9 (2013) 3336-3344. [3] Y. He, J. Cai, T. Li, Y. Wu, H. Lin, L. Zhao, M. Luo, Chem. Eng. J. 215-216 (2013) 721-730. [4] T. Li, L. Zhao, Y. He, J. Cai, M. Luo, J. Lin, Appl. Catal. B 129 (2013) 255-263. [5] K. Li, S.M. Gao, Q.Y. Wang et al., ACS Appl. Mater. Interfaces 7(2015) 9023-9030. [6] W. Zhou, H.G. Fu, K. Pan et al., J. Phys. Chem. C 112 (2008) 19584-19589. [7] J. Li, M. Zhang, Q. Y. Li, J. J. Yang, Appl. Surf. Sci. 391 (2017) 184–193

95

Wuhan, China

Poster Presentation PP28

Green synthesis of silver nanoparticle - reduced graphene oxide using Psidium guajava and its application in SERS for the detection of methylene blue Prajwal Chettri a, V. S. Vendamani b, Ajay Tripathi a, Manish Kumar Singh c, Anand P. Pathak b, Archana Tiwari a,* a

Department of Physics, School of Physical Sciences, Sikkim University, Gangtok 737102, India b School of Physics, University of Hyderabad, Hyderabad 500046, India c Department of Metallurgical Engineering, IIT (BHU), Varanasi 221005, India Email address: [email protected]

Abstract: Various chemical routes have been utilised for the synthesis of metal nanoparticle (MNP)-graphene composites where simultaneous reduction of metal salt and graphene oxide (GO) occurs [1, 2, 3]. Due to the toxic effects of the chemicals used, several green techniques have been applied for the synthesis [4, 5, 6]. MNP-graphene composites synthesised via these techniques have limited reports on surface enhanced Raman scattering activity (SERS), its enhancement factor (EF) and photoluminescence (PL) quenching efficiency. Here we present the synthesis of reduced graphene oxide (rGO) and silver nanoparticle – rGO (Ag-rGO) composites using aqueous extract of dry leaves of Psidium guajava (PG) as a reducing agent. PG extract simultaneously reduces silver nitrate and GO in the reaction mixture which is confirmed by various spectroscopic techniques. The SERS and PL quenching efficiency of these materials have been examined using methylene blue (MB) dye as the probe molecule and the EF and PL quenching constants have been evaluated. For SERS measurements varying concentration of silver nitrate solution are used to obtain rGO with different dosage of silver nanoparticles (AgNP). It is found that the SERS activity increases with the increase in the dose of AgNP. Our as-synthesised Ag-rGO composite shows remarkable performance in detecting MB with concentration as low as 10 -8 M for which the EF is 4.6 X 105. To the best of our knowledge this is the first report based on the use of phytoextracts for the synthesis of Ag-rGO and its subsequent utilization in SERS activity with an EF > 10 5. Apparently, the obtained value of EF surpasses those achieved by any other green routes [4, 5, 7]. Unlike other reports, rGO quenches the PL of MB more efficiently than Ag-rGO composite for which the charge transfer states have been extracted which are mainly responsible for the quenching processes.

Keywords: silver nanoparticle – reduced graphene oxide, Psidium guajava, SERS, Methylene blue, Fluorescence quenching, Charge transfer. [1] S. Murphy, L. Huang, P. V. Kamat, J. Phys. Chem. C 117 (2013) 4740-4747. [2] S. Dutta, C. Ray, S. Sarkar, M. Pradhan, Y. Negishi, T. Pal, ACS Appl. Mater. Interfaces 5 (2013) 8724-8732. [3] B. Yang, Z. Liu, Z. Guo, W. Zhang, M. Wan, X. Qin, et al., Appl. Surf. Sci. 316 (2014) 22-27. [4] W. L. Fu, S. J. Zhen, C. Z. Huang, Analyst 138 (2013) 3075-3081. [5] Y. Zhang, S. Liu, L. Wang, X. Qin, J. Tian, W. Lu, et al., RSC Adv. 2 (2012) 538-545. [6] K. Hareesh, J. F. Williams, N. A. Dhole, K. M. Kodam, V. N. Bhoraskar, S. D. Dhole, Mater. Res. Express 3 (075010) (2016) 1-9. [7] Q. Huang, J. Wang, W. Wei, Q. Yan, C. Wu, X. Zhu, J. Hazard. Mater. 283 (2015) 123-130.

96

Wuhan, China

Poster Presentation PP29

Various morphology of cuprous oxide nanoparticles: ionic liquidassisted synthesis and photocatalytic performance Lulu Liu, Yubo Xie, Yang Xuan, Kezhen Qi* Institute of Catalysis for Energy and Environment, College of Chemistry and Chemical Engineering, Shenyang Normal University, Shenyang, 110034, China *Email: [email protected]

Abstract: As assistance by ionic liquid, the Cu2O crystal was successfully synthesized by hydrothermal method, including cathedrals, truncated octahedrals, facet-etched octahedrals, particle-coated ocahedrals and aggregated spheres (see Figure 1). The morphology of Cu2O crystals can easily be modified by turning the adding amounts of ionic liquid 1-ethyl-3methylimidazolium bromide. Under visible-light irradiation (λ > 420 nm), the obtained Cu2O samples show an outstanding performance during photodegrading methylene blue (MB) dye. The higher photocatalytic activity for MB photodegradation by the Cu2O facet-etched octahedrals comparing to octahedrals can be attributed to the formation of surface heterojunction between (100) and (111) facets. Therefore, the ionic liquid-assisted hydrothermal route syntheses would be potentially used in the fields of catalysts production industry for photodegrading hazard pollutants.

Figure 1. Diagram showing the evolution in the shape of Cu2O crystals as the IL concentration changing. Keywords: Cuprous oxide, morphology control • ionic liquid • DFT calculation • photocatalytic activity

97

Wuhan, China

Poster Presentation PP30

The exfoliation of Fe2O3 interlayered bulk g-C3N4 to ultrathin g-C3N4 with enhanced photocatalytic performance Yongning Ma a, Enzhou Liu a,b,c, Juan Li a, Xiaoyun Hu b, and Jun Fan a* a

School of Chemical Engineering, Northwest University, Xi’an 710069, PR China b School of Physics, Northwest University, Xi’an 710069, PR China c Institute of Modern Physics, Northwest University, Xi’an 710069, PR China Corresponding authors e-mail: [email protected]

Abstract: The ultrathin g-C3N4 has many intriguing properties different from bulk g-C3N4 and

present potential in diverse applications[1-3]. Many strategies have been developed to fabricate ultrathin g-C3N4 with few-layer structures, especially nanosheets with single atomic layer. However, the strong Van der Waals' force is the most obstacles in exfoliation process, and the direct ultrasonic exfoliation is time-consuming and low efficiency. Herein, ultrathin g-C3N4 with fewlayer structures and single-layer structures are prepared by chemical exfoliation process employing bulk g-C3N4 as precursor which was firstly intercalated by Fe2O3 particles. The as-prepared samples were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Fourier-transform infrared spectroscopy, UV-vis absorption spectra, and photoluminescence spectroscopy, respectively. The AFM and TEM images indicate that intercalated bulk g-C3N4 can be easily exfoliated to ultrathin g-C3N4 and the thickness of ultrathin g-C3N4 is only 4.6 nm and the size of Fe2O3 particles is about 50 nm. According to the PL spectroscopy, the ultrathin g-C3N4 can suppress the recombination of photo-induced electron-hole pairs. Furthermore, the as-prepared ultrathin g-C3N4 exhibits an enhanced photo-catalytic performance in the degradation of RhB (Rhodamine B).

Fig.1 SEM (a), AFM (b) and TEM (c and d) images of Fe2O3 deposited ultrathin g-C3N4

Fig.2 (a) the degradation curve and (b) the first order kinetics of RhB

Key words: Fe2O3; g-C3N4; photo-catalytic; layered materials; chemical exfoliation. [1] J. Ong, L. L. Tan, Y. H. Ng, S. T. Yong, S. P. Chai, Chem. Rev., 2016, 116, 7159. [2] G. P. Gao, Y. Jiao, E. R. Waclawik, A. J. Du, J. Am. Chem. Soc., 2016,138, 6292-6268. [3] Y. D. Hou, Y. S. Zhu, Y. Xu, X. C. Wang, Appl. Catal. B Environ., 2014, s156–157,122–127.

98

Wuhan, China

Poster Presentation PP31

In situ construction of g-C3N4/TiO2 heterojunction film with enhanced light-harvesting ability for efficient photocatalysis Chao Pan a, Yongning Ma a, Jun Wan a, Enzhou Liu a,b,c*, Xiaoyun Hu b, and Jun Fan a* a

School of Chemical Engineering, Northwest University, Xi’an 710069, PR China b School of Physics, Northwest University, Xi’an 710069, PR China c Institute of Modern Physics, Northwest University, Xi’an 710069, PR China Corresponding authors e-mail: [email protected] and [email protected]

Abstract: g-C3N4 and TiO2 have attracted a great deal of attention in photocatalysis field due to their long-term stability and environmentally friendly features. The combination of these two photocatalysts can obtain highly efficient photocatalyst based on the heterojunction effect, which can effectively restrain the recombination of the electrons and holes, leading to excellent photocatalytic activities. However, it remains a great challenge to develop highly active gC3N4/TiO2 heterojunction with high stability and explore the large-scale preparation methods. Herein, Corn-shaped TiO2 nanofilm was successfully prepared by glycerol-assisted hydrothermal method, and then g-C3N4 nanoparticles were deposited on TiO2 film using urea as starting material under air atmosphere in a microwave muffle furnace (Fig. 1(a) and (b)). The investigations indicate that it is a facile strategy to preparation g-C3N4 by thermal polymerization of urea by microwave treatment, and in situ deposition of g-C3N4 nanoparticles on TiO2 film can obtain highly stable heterojunction photocatalysts. Besides, the Corn-shaped TiO2 film exhibit excellent visible light scattering property, the scattering light overlaps with the absorption light of g-C3N4, which can enhance the utility of incident light. The photocatalytic performance of samples was evaluated by degradation Rhodamine (RhB), the composite exhibited a much higher degradation rate of RhB than the unmodified TiO2 nanofilm under visible light (Fig. 1(c)). The enhanced photocatalytic activity could be attributed to the overlapped visible light absorption, large content surface area, and effective electron-hole separation at the interfaces of the two semiconductors, which was confirmed by photoluminescence (PL) and photoelectrochemical tests. 1.0

C/C0

0.8

35.2%

0.6 0.4

TiO2 film g-C3N4/TiO2 film

0.2

94.8%

0.0 -30

(a)

(b)

0

30

60

90

Time（min）

120

150

(c)

Fig 1. SEM images of (a) Corn-shaped TiO2 nanofilm and (b) g-C3N4/TiO2 heterojunction film, and (c) Plots of C/Co versus the irradiation time for RhB aqueous solution over different samples under visible light irradiation

Keywords: g-C3N4 • TiO2 nanofilm • light-harvesting • In situ preparation • heterojunction [1] [2] [3] [4] [5]

J. Liu, B. Cheng, J. Yu, Phys. Chem. Chem. Phys., 2016, 18, 31175-31183 S. Cao, J. Yu, J. Phys. Chem. Lett., 2014, 5, 2101-2107 X. Li, J. Yu, M. Jaroniec, Chem. Soc. Rev., 2016, 45, 2603-2636 R. Mohini, N. Lakshminarasimhan, Mater. Res. Bull., 2016, 76, 370-375 T. Giannakopoulou, I. Papailias, N. Todorova, et al., Chem. Eng. J., 2017, 310, 571-580

99

Wuhan, China

Poster Presentation PP32

Enhanced Solar-driven Hydrogen Evolution using All-solid-state Zscheme Photocatalyst with Carbon Nanotubes as Electron Mediator** Boon-Junn Ng, Lutfi Kurnianditia Putri, Pooria Pasbakhsh, and Siang-Piao Chai* Address: (of Affiliation): Multidisciplinary Platform of Advanced Engineering, Chemical Engineering Discipline, School of Engineering, Monash University, Jalan Lagoon Selatan, 47500 Bandar Sunway, Selangor, Malaysia e-mail: [email protected]

Abstract: Owing to the global energy consumption continues to escalate and the incapability of the energy replenishment from finite traditional resources to fulfil such needs, a transition of energy supply to a more promising carrier, namely hydrogen (H 2), is anticipated in the near future. Hitherto, biomimetic artificial Z-scheme photocatalytic system which resembles photosynthesis in green plant has drawn world attention as one of the many endeavours in harvesting H 2 energy. A recreation of this system has been witnessed in the light-driven Z-scheme water splitting system which utilizes an electron mediator with two semiconductors that are ingeniously arranged in a nano-platform [1]. For years, Z-scheme photocatalytic water splitting studies have been widely conducted by employing ionic electron mediator such as IO 3-/I- and Fe3+/Fe2+ [2, 3]. However, the redox-pair aided Z-scheme system often suffers from backward reaction and shielding effect [4]. In this regard, a transition of electron transporter to a redox-pair free solid-state mediating system keenly desirable. The versatile tailoring and excellent intrinsic properties of MWCNTs and graphene have triggered a huge interest towards designing nanocarbon-mediated Z-scheme system. This is due to the competency of carbonaceous materials in transferring electrons by attaining a charge equilibrium with the surrounding medium upon photoexcitation (1 electron per 32 carbon atoms) [5]. There has been an incessant endeavour in constructing Z-scheme system using graphene as the electron mediator. In this context, MWCNTs is worth noting as a promising mediator candidate as it possesses unique electronic properties similar to graphene and is rarely been investigated. Herein, we report a fine-tuned MWCNT-mediated Z-scheme system which govern Zn0.5Cd0.5S as the H2 photocatalyst (PS I) and TiO2 as the O2 photocatalyst (PS II). The ternary nanocomposites (Zn0.5Cd0.5S-MWCNT-TiO2) fabricated by a facile two-step coating and hydrothermal route displayed a synergistic effect that leads to a massive improvement in photocatalytic activity over the corresponding single- and two-component systems, revealing that MWCNTs can shuttle efficient electron transport from PS II (TiO 2) to PS I (Zn0.5Cd0.5S). This peculiar type of vectorial electron transfer between the two photosystems render an efficient spatial charge isolation and bestow suitable relative band positions with strong redox ability to the Zscheme system. Consequently, the as-prepared Z-schematic Zn0.5Cd0.5S-MWCNT-TiO2 photocatalyst demonstrated a photocatalytic H2 production of 21.9 µmol h-1 under simulated solar light (AM 1.5), which is ca. 4.5- and 2.8-fold augmentation over pristine Zn0.5Cd0.5S and MWCNTZn0.5Cd0.5S respectively [6]. The intimate contact between the photosystems and MWCNTs imparts a low contact resistance interface for the vectorial electron transfer, namely Ohmic contact [7]. In all, these findings could extend the electron mediator candidates to a larger area and pave a future way in the field of Z-scheme photocatalytic H2 production. Keywords: Z-scheme • Water splitting • Carbon nanotubes • Photocatalyst • Hydrogen [1] H. Tada, T. Mitsui, T. Akita, K. Tanaka, Nat. Mater., 2006, 5, 782-786 [2] K. Maeda, M. Higashi, D. Lu, R. Abe, K. Domen, J. Am. Chem. Soc., 2010, 132, 5858-5868 [3] Y. Sasaki, A. Iwase, H. Kato, A. Kudo, J. Catal., 2008, 259, 133-137 [4] P. Zhou, J. Yu, M. Jaroniec, Adv. Mater., 2014, 26, 4920-4935 [5] A. Kongkanand, P. V. Kamat, ACS Nano, 2007, 1, 13-21 [6] B. –J. Ng, L. K. Putri, L. –L. Tan, P. Pasbakhsh, S. –P. Chai, Chem. Eng. J., 2017, 316, 41-49 [7] H. B. Yang, J. Miao, S. –F. hung, F. Huo, H. M. Chen, B. Liu, ACS Nano, 2014, 8, 10403-10413

100

Wuhan, China

Poster Presentation PP33

Room temperature in-situ fabrication of direct Z-scheme Bi2O3/g-C3N4 composite photocatalyst and its enhanced photocatalytic activity Rongan He*, Jiaqian Zhou, Huiqing Fu, Difa Xu, Shiying Zhang, Yanhua Li Address: Hunan province key laboratory of applied environmental photocatalysis, Changsha University, Changsha 410022, China e-mail: [email protected]

Abstract: Constructing direct Z-scheme is an effective way to improve the performance of photocatalyst. It could prolong the lifetime of more reactive carriers by facilitating the recombination of some less reactive holes and electrons. In this work, a direct Z-scheme composites comprised of ω-Bi2O3 quantum dots (QDs) and graphic C3N4 (g-C3N4) was fabricated by a facile insitu deposition and oxidation method at room temperature, using g-C3N4 as the support of Bi2O3, whose proportion is about 3wt%. The as prepared Bi2O3/g-C3N4 composite exhibited higher photocatalytic performance than pure α-Bi2O3 and g-C3N4 in photocatalytic degradation of phenol under visible light (λ > 400 nm). The enhancement of photocatalytic activity of Bi2O3/g-C3N4 is attributed to the key role of the Z-scheme migration of electrons, from the conduction band of Bi2 O3 to the valance band of g-C3N4. Such a kind of electron migration was reflected by the blue shift of Bi 4f, red shift of C1s and N1s of Bi2O3/g-C3N4, as well as the stronger photoluminescence emission and higher ∙OH generation of Bi2O3/g-C3N4. The fabrication methods might also provide new sight for the design of other photocatalysts with heterojunction.

Keywords: Direct Z-scheme • Bi2O3 • g-C3N4 • room-temperature synthesis • photocatalysis [1] [2] [3] [4] [5]

P. Zhou, J. G. Yu, M. Jaroniec, Adv. Mater., 2014, 26, 4920-4935 S. W. Cao, J. X. Low, J. G. Yu, M. Jaroniec, Adv. Mater., 2015, 27, 2150-2176 J. Wen, J. Xie, X. Chen, X. Li, Appl. Surf. Sci., 2017, 391, 72-123 B. Zhu, P. Xia, Y. Li, W. Ho, J. Yu, Appl. Surf. Sci., 2016, 391, 175-183 H. Y. Jiang, G. G. Liu, T. Wang, P. Li, J. Lin, J. H. Ye, RSC Adv., 2015, 5, 92963-92969

101

Wuhan, China

Poster Presentation PP34

Preparation of nanostructured lamellar materials in molten salts** Jing Zhou*, Wei Xiao, Dihua Wang Address: (of Affiliation): School of Resource and Environmental Sciences, Wuhan University, Wuhan, China e-mail: [email protected]

Abstract: Strong capability on dissolving and/or absorbing reactants, enhanced reaction kinetics at elevated temperatures, and high heat capacity make inorganic high-temperature molten salts (MSs) ideal reaction media for massive production. In particular, cations and anions in MSs can effectively retard overgrowth of nuclei and agglomeration of tiny particles, facilitating formation of ultrafine nanostructured materials. Also, species tends to occur in less solvated states in MSs. Such species can occupy tunnels and interlayer gaps in lattices, which could stabilize such tunnelled and layered structures. Therefore, MSs can be promising reaction media for preparation of layered nanostructured materials. Herein, two kinds of typical lamellar nanomaterials, i.e. g-C3N4 and MoS2 are prepared in molten chlorides and molten carbonates. The synthetic parameters and the composition/microstructure of the obtained samples are discussed and rationalized, which, we hope, could form a solid basis for controllable preparation of nanostructured layered materials in MSs.

TEM images of the obtained few-layered MoS2 coated on carbon nanotubes (left panel) and the obtained gC3N4 quantum dots (right panel) * Presenter This work was funded by the National Natural Science Foundation of China (51325102), the International Science & Technology Cooperation Program of China (ISTCPC, 2015DFA90750), the Program for Creation Team of Hubei Province (2015CFA017), and the Young-talent Chenguang Project of Wuhan City.

102

Wuhan, China

Poster Presentation PP35

Molten-salt-assisted preparation of ultrathin/ultrafine lamellar nanostructured materials** Chen Zeng, Ni Li, Teng Lv, Jing Zhou, Wei Xiao* School of Resource and Environmental Sciences, Wuhan University, Wuhan, China E-mail: [email protected]

Abstract: Strong capability on dissolving and/or absorbing reactants, enhanced reaction kinetics at elevated temperatures, and high heat capacity make inorganic high-temperature molten salts (MSs) ideal reaction media for massive production. In particular, cations and anions in MSs can effectively retard overgrowth of nuclei and agglomeration of tiny particles, facilitating formation of ultrathin/ultrafine nanostructured materials. Also, species tends to occur in less solvated states in MSs. Such less-solvated species can occupy tunnels and interlayer gaps in lattices, which could stabilize such tunnelled and layered structures. Therefore, MSs can be promising reaction media for preparation of ultrathin/ultrafine layered nanostructured materials. Herein, two kinds of typical lamellar nanomaterials, i.e. g-C3N4 and MoS2 are prepared in molten chlorides and molten carbonates. The synthetic parameters and the composition/microstructure of the obtained samples are discussed and rationalized, which, we hope, could form a solid basis for controllable preparation of nanostructured layered materials in MSs. Keywords: Two-dimensional materials• Molten salt preparation • C3N4 • MoS2 • ultrathin/ultrafine [1] B. Lu, J. Zhou, Y. Song, H. Wang, W. Xiao, D. Wang, Faraday Discussions, 2016, 190, 147-159 [2] L. Pi, R. Jiang, W. Zhou, H. Zhu, W. Xiao, D. Wang, X. Mao, Applied Surface Science, 2015, 358, 231-239

103

Wuhan, China

Poster Presentation PP36

Reduced Graphene Oxide in Ag2CO3 Photocatalyst: A Double-edged Sword to Photocatalytic Activity and Cycling Stability Wenguang Wang*, Yuan Liu, Haiyan Zhang, Yannan Qian, and Zuchen Guo Address: School of Materials and Energy, Guangdong University of Technology, Guangzhou Higher Education Mega Center 100#, Guangzhou, 510006, P. R. China E-mail: [email protected]

Abstract: Coupling graphene or reduced graphene oxide (RGO) with semiconductor photocatalysts has previously been proven to be an effective way for enhancing the photocatalytic activity and stability of the photocatalysts. Herein, the Ag2CO3/reduced graphene oxide composite was successfully prepared by a facile chemical precipitation method. The physical and chemical properties of the photocatalysts were characterized by X-ray diffraction, Raman spectra, scanning electron microscope, X-ray photoelectron spectroscopy, UV-vis diffuse-reflection spectra. The photocatalytic activity and cycling stability of the photocatalysts were evaluated by photocatalytic degradation of rhodamine B under visible light irradiation. The results showed that the RGO indeed improves the photocatalytic activity of Ag2CO3/RGO, which can be attributed to the reduced charge recombination and enhanced dye adsorption as well as the light capture by RGO. Nevertheless, it played a negative role to the photocatalytic cycling stability due to the strong aggregation of Ag2CO3 particles brought by the RGO sheets. This work may provide a re-examination of the role of RGO for enhancing the photocatalytic performances of the photocatalysts.

Figure.1 The schematic illustration for the morphology change of pure Ag2CO3 and Ag2CO3/RGO composite during the synthesis and after multiple cycle experiments.

Keywords: reduced graphene oxide • silver carbonate • visible light • photocatalytic activity • cycling stability [1] [2] [3] [4] [5]

W.G. Wang, Y. Liu, H.Y Zhang, Y.N. Qian, Z.C. Guo, Appl. Surf. Sci., 2010, 39, 4206-4219. C.C. Chen, W.H. Ma, J.C. Zhao, Chem. Soc. Rev., 2010, 39, 4206-4219. J.G. Yu, W.G. Wang, B. Cheng, B.L. Su, J. Phys. Chem. C, 2009, 113, 6743-6750. G.P. Dai, J.G. Yu, G. Liu, J. Phys. Chem. C, 2012, 116, 15519-15524. Z.G. Yi, J.H. Ye, N. Kikugawa, T. Kako, S.X. Ouyang, H. Stuart-Williams, H. Yang, J.Y. Cao, W.J. Luo, Z.S. Li, Y. Liu, R.L. Withers, Nat. Mater., 2010, 9, 559-564. [6] H.J. Dong, G. Chen, J.X. Sun, C.M. Li, Y.G. Yu, D.H. Chen, Appl. Catal. B: Environ., 2013, 134-135, 46-54. [7] L. Shi, L. Liang, F.X. Wang, M.S. Liu, J.M. Sun, J. Mater. Sci., 2015, 50, 1718-1727. [8] C.L. Yu, L.F. Wei, W.Q. Zhou, J.C. Chen, Q.Z. Fan, H. Liu, Appl. Surf. Sci., 2014, 319, 312-318. [9] W.G. Wang, J.G. Yu, Q.J. Xiang, B. Cheng, Appl. Catal. B: Environ., 2012, 119-120, 109-116. [10] S.Q. Song, B. Cheng, N.S. Wu, A.Y. Meng, S.W. Cao, J.G. Yu, Appl. Catal. B: Environ., 2016, 181, 71-78.

104

Wuhan, China

Poster Presentation PP37

A novel ternary Ag/CeVO4/g-C3N4 nanocomposite with enhanced visible-light photocatalytic activity for organic dye decomposition Jie Ren, Yanze Wu, Jianmei Pan, Hua Tang, Xiaonong Cheng and Xuehua Yan* Institute for advanced Materials, School of Materials Science and Engineering, Jiangsu University, Zhenjiang, Jiangsu, China e-mail: [email protected]

Abstract: The CeVO4/graphitic C3N4 composites were successfully synthesized by using a calcination method, which compared with single-phase g-C3N4 and CeVO4 exhibit much enhanced photocatalytic property in degrading methylene blue (MB) pollutant under visible light irradiation [1]. The optimized mass ratio of CeVO4 and DCDA as raw materials is 5%, then the obtained composite was denoted as S5. Here, the ternary nanocomposites were prepared by an ultrasonic precipitation method using S5, silver nitrate and sodium citrate, and denoted as X%Ag/S5. The TEM images show that CeVO4 and Ag particles are well distributed on the layered g-C3N4, where CeVO4 has an average particle size of 50 nm as well as Ag particle size of 10 nm. The XRD results show that there are two peaks corresponding to (111) and (200) lattice planes of Ag, indicating that we successfully prepare the nanocomposites with ternary phases. The UV spectra show that the 7%Ag/S5 sample has the largest absorption range and intensity of visible light. The corresponding band gap is 2.65 eV, much lower than that of S5. The degradation experiments for MB solution suggest that 7%Ag/S5 has the optimal photocatalytic performance, which can degrade MB solution completely within 120 min. The corresponding k value is 0.0462 min-1, much higher than those of g-C3N4 and CeVO4. The enhanced photocatalytic property of the composites is ascribed to not only the effect of heterojunction structure but also the surface plasma resonance effect of Ag nanoparticles.

Keywords: C3N4 • CeVO4 • Ag • Nanocomposites • Photocatalytic performance [1] J. Ren, Y.Z. Wu, H. Zou, Y. Dai, D.W. Sha, M. Chen, J.J. Wang, J.M. Pan, X.H. Yan, Mater. Lett., 2016, 183, 219-222

105

Wuhan, China

Poster Presentation PP38

Enhanced visible-light photo-oxidation of nitric oxide using bismuth-coupled graphitic carbon nitride composite heterostructures Yuhan Li a, Kangle Lv a,c,*, WingKei Ho a,b,*, Zaiwang Zhao a, Yu Huangb a Department of Science and Environmental Studies, The Education University of Hong Kong, Tai Po, N.T., Hong Kong, China b Key Laboratory of Aerosol Chemistry and Physics, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an 710061, Shanxi, China c Key Laboratory of Catalysis and Materials Science of the State Ethnic Affairs Commission and Ministry of Education, College of Resources and Environmental Science, South‐Central University for Nationalities, Wuhan 430074, Hubei, China E-mail: [email protected] E-mail: [email protected]

Abstract: The potential for noble metal-based materials to harvest and convert solar energy has garnered considerable attention in recent years [1]. In view of expense of precious metals, some affordable and readily available metals possessing similar electronic and light-absorption characteristics to those of noble metals have been investigated as substitutes [2]. It is well documented that the semimetal bismuth (Bi) behaves as a photocatalyst with promising photocatalytic performance [2]. Therefore, in this study, pure bismuth (Bi) metal-modified graphitic carbon nitride (g-C3N4) composites (Bi-CN) with a pomegranate-like structure were prepared by an in situ method. The Bi-CN composites were used as photocatalysts for the oxidation of nitric oxide (NO) under visible-light irradiation. The inclusion of pure Bi metal in the g-C3N4 layers markedly improved the light absorption of the Bi-CN composites from the ultraviolet to the near-infrared region because of the typical surface plasmon resonance of Bi metal. The separation and transfer of photogenerated charge carriers were greatly accelerated by the presence of built-in Mott–Schottky effects at the interface between Bi metal and g-C3N4. As a result, the Bi-CN composite photocatalysts exhibited considerably enhanced efficiency in the photocatalytic removal of NO compared with that of Bi metal or g-C3N4 alone. The pomegranate‐like structure of the Bi-CN composites and an explanation for their improved photocatalytic activity were proposed. This work not only provides a design for highly efficient g-C3N4-based photocatalysts through modification with Bi metal, but also offers new insights into the mechanistic understanding of g-C3N4-based photocatalysis.

Keywords: Bismuth • Surface plasmon resonance • Photo‐oxidation • Nitric oxide • Visible light• Graphitic carbon nitride [1] Y.H. Li, L.P. Yang, G.H. Dong, W.K. Ho, Molecules, 2016, 21,36-46. [2] F. Dong, Q.Y. Li, Y.J. Sun, W.K. Ho, ACS Catal., 2014, 4, 4341-4350.

106

Wuhan, China

Poster Presentation PP39

Effect of Carbon-dots Modification on the Structure and Photocatalytic Activity of g-C3N4 Shun Fang, Yang Xia, Kangle Lv *, Qin Li, Jie Sun, Mei Li * Key Laboratory of Catalysis and Materials Science of the State Ethnic Affairs Commission & Ministry of Education, South - Central University for Nationalities, Wuhan 430074, P.R. China *Corresponding author: [email protected] (K.L. Lv); [email protected] (M. Li)

Abstract: As a promising metal-free photocatalyst, graphitic carbon nitride (g-C3N4) has attracted increasing attention. However, from the viewpoint of practical application, the quantum efficiency of g-C3N4 needs to be further improved. In this article, carbon dots (C-dots) modified g-C3N4 hybrid was successfully prepared by a novel strategy using C-dots and dicyandiamide as starting materials. The photocatalyst was characterized by scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), FT-IR, UV-Vis diffuse reflectance spectrum (DRS), X-ray photoelectron spectroscopy (XPS), powder photoluminescence (PL) and surface photovoltage spectrum (SPS). Both the photocatalytic activity of C-dots modified g-C3N4 was evaluated by degradation of Rhodamine B under UV irradiation and photocatalytic hydrogen production under visible irradiation. The experimental results show that C-dots modification causes the lattice distortion of g-C3N4. With increase in the loading amount of C-dots, the photocatalytic activity of gC3N4 increase first and then decrease. g-C3N4 modified with 0.25 wt.% C-dots shows the highest photocatalytic activity, which is 3 times higher than pristine g-C3N4. C-dots act as electron-sinks, which prevent the recombination of photo-generated electron-hole pairs, enhancing the photocatalytic activity of g-C3N4. However, too much C-dots become recombination centers, which is detrimental to the photocatalytic activity of g-C3N4.

Scheme 1. Schematic diagram showing one-pot synthesis of C-dots modified g-C3N4 with enhanced photocatalytic activity.

Keywords: Graphitic carbon nitride • Carbon dot • Photocatalytic degradation • Rhodamine B [1] H. Liu, T. Ye, C. Mao, Angew. Chem. Int. Ed., 2007, 46, 6473-6475. [2] X.C. Wang, K. Maeda, A. Thomas, K. Takanabe, G. Xin, J.M. Carlsson, K. Domen, M. Antonietti, Nat. Mater., 2009, 8, 76-78. [3] J. Liu, Y. Liu, N.Y. Liu, Y.Z. Han, X. Zhang, H. Huang, Y. Lifshitz, S.T. Lee, J. Zhong, Z.H. Kang, Science, 2015, 347, 970-974. [4] S. Fang, K.L. Lv, Q. Li, H.P. Ye, D.Y. Du, M. Li, Appl. Surf. Sci., 2015, 358, 336-342. [5] S. Fang, Y. Xia, K.L. Lv, Q. Li, J. Sun, M. Li, Appl. Catal. B, 2016, 185, 225-232.

107

Wuhan, China

Poster Presentation PP40

Hybridization of rutile TiO2 (rTiO2) with g-C3N4 quantum dots (CN QDs): An efficient visible-light-driven Z-scheme hybridized photocatalyst Yuhan Li a, Kangle Lv a,b,*, Wingkei Ho a*, Fan Dong c a Department of Science and Environmental Studies, The Education University of Hong Kong, Tai Po, N.T., Hong Kong, China b Key Laboratory of Catalysis and Materials Science of the State Ethnic Affairs Commission and Ministry of Education, College of Resources and Environmental Science, South-Central University for Nationalities, Wuhan, 430074, PR China c Chongqing Key Laboratory of Catalysis and Functional Organic Molecules, College of Environmental and Biological Engineering, Chongqing Technology and Business University, Chongqing, 400067, PR China E‐mail: [email protected] (K. Lv); [email protected] (W. Ho)

Abstract: To make full use of solar light and improve the photocatalytic activity, fabrication of gC3N4 quantum dots (CN QDs) [1, 2] modified rutile TiO2 (rTiO2) hybrid (CN QDs-rTiO2), using both visible light responsive semiconductors as components, was successfully achieved by calcination the mixture of P25 TiO2 and melamine at 500 ℃ for 4 h. It was found that CN QDs were in-situ formed during calcination, which were homogeneously deposited on the surface of rTiO2. Modification of rTiO2 by CN QDs not only improved the visible-light harvesting ability, but also retarded the recombination of photogenerated electron-hole pairs. CN QDs-rTiO2 hybrid (S15) with nominal 15 at.% CN QDs loading showed the highest photocatalytic activity among all the photocatalysts, whatever for degradation of RhB or photocatalytic decomposition of NO, under visible light irradiation. The increased formation of •OH radicals in CN QDs modified rTiO 2 suspensions supports a Z-Scheme degradation mechanism instead of the formation of CN QDsrTiO2 heterojunctions.

(Left) Fig. 1. TEM image of bulk g-C3N4 (a), HR TEM images of rTiO2 (b), S15 sample (c) and CN QDs (d). The yellow circles represent the presence of CN QDs. (Right) Scheme 1. Photocatalytic degradation mechanism of CN QDs-rTiO2 hybrid for RhB degradation and NO removal under visible-light irradiation. Keywords: g-C3N4 • Rutile TiO2 • Quantum dots Photocatalytic degradation • Visible-light [1] X.D. Zhang, H.X. Wang, H. Wang, Q. Zhang, J.F. Xie, Y.P. Tian, J. Wang, Y. Xie, Adv. Mater., 2014, 26, 4438-4443. [2] X. Chen, Q. Liu, Q.L. Wu, P.W. Du, J. Zhu, S.Y. Dai, S.F. Yang, Adv. Funct. Mater., 2016, 26, 1719-1728.

108

Wuhan, China

Poster Presentation PP41

Effect of mesoporous g-C3N4 substrate on catalytic oxidation of CO over Co3O4** Heng Yang, Kangle Lv*, Junjiang Zhu* Address: Key Laboratory of Catalysis and Materials Science of the State Ethnic Affairs Commission and Ministry of Education, College of Resources and Environmental Science, South-Central University for Nationalities, Wuhan, China. e-mail: [email protected] (K. Lv), [email protected] (J. Zhu).

Abstract: Mesoporous graphitic carbon nitride (mpg-CN) was synthesized using Triton X-100, a surfactant containing a hydrophilic polyethylene oxide group and a tert-octyl-phenyl hydrophobic moiety, as a soft template. The obtained mpg-CN was used as a support for Co 3O4, and this supported catalyst was used for CO oxidation. The effects of the amount of Triton X-100, weight ratio of Co3O4 to mpg-CN and calcination temperature on the catalytic performances for CO oxidation of Co3O4/mpg-CN composites were systematically studied. It was found that the presence of Triton X-100 not only retarded the polymerization of dicyandiamide, but also affected the microstructure of Co3O4. Bubbles formed because of the hydrophobic group of the surfactant Triton X-100 can be act as a soft template for the synthesis of mesoporous g-C3N4. The enhanced catalytic activity of Co3O4/mpg-CN was attributed to a synergistic effect, enlarged BET surface areas, increased Co3+ and lattice oxygen contents, and the porous structure of mpg-CN support. The high stability of 12.5% Co3O4/mpg-CN(1.0) makes it a promising catalyst for practical applications. .

Fig. 1. SEM images of Co3O4 nanoparticles supported on bulk g-CN(A) and mpg-CN(B)

Fig. 2. Effects of substrate (A) and Co3O4 loading amount (B) on the catalytic oxidation of CO over Co3O4, and the stability of 12.5%Co3O4/mpg-CN(1.0) catalyst (C).

Keywords: Co3O4 • CO oxidation • mesoporous g-C3N4 • Triton X-100 • dicyandiamide [1] J.J. Zhu, S.A.C. Carabineiro, D. Shan, J.L. Faria, Y.J. Zhu, J.L. Figueiredo, J. Catal., 2010, 274, 207–214. [2] J.J. Zhu, P. Xiao, H.L. Li, S.A.C. Carabineiro, ACS Appl. Mater. Interfaces., 2014, 6, 16449–16465. [3] H. Yang, Kangle Lv, Junjiang Zhu, Qin Li, Dingguo Tang, Wingkei Ho, Mei Li, Sónia A.C. Carabineiro, Appl. Surf. Sci., 2017, 401, 333-340.

109

Wuhan, China

Poster Presentation PP42

Photocatalytic hydrogen production from methanol over Nd/TiO2 Martin Reli a*, Miroslava Edelmannováa, Ivana Troppováa, Libor Čapek b, Kamila Kočí a Address: a Institute of Environmental Technology, VŠB-Technical University of Ostrava, 17. listopadu 15/2172, Ostrava, 70833, Czech republic, e-mail: [email protected] b Faculty of Chemical Technology, University of Pardubice, Studentská95, 532 10 Pardubice, Czech Republic.

Abstract: The question of renewable energy is becoming more and more frequent these days. Not only because the fossil fuels are becoming to be scarce but also due to increasing environment pollution caused by combustion of fossil fuels. Besides utilizing the elements like wind, sun or water, a new more reliable way of clean energy production is being seek out. One of such possibility is the photocatalytic oxidation of low alcohols, for example methanol. Not only, this reaction is environmentally friendly, but also is a promising way, how to replace obsolete fossil fuel combustion. This work is focused on a modification of titanium dioxide by neodymium. Lanthanides possess 4f electron configuration, which can significantly improve photocatalytic activity of TiO2. The partly filled 4f electrons in rare earth ions can form a new energy level between the TiO2 valence and conduction bands resulting in narrowed band gap [1,2]. Three different TiO2 photocatalysts have been prepared by various methods, tested for the photocatalytic oxidation of methanol and compared to commercial TiO 2 Evonik P25. At first, TiO2 was prepared by sol-gel method followed by either calcination or processing by pressurized water at high temperature. The temperature at high pressure processing is very important, therefore two samples at two different temperatures (200 °C and 225 °C) were prepared. These differently prepared pure TiO2 photocatalysts were tested for photocatalytic oxidation of methanol. Based on the yields of generated hydrogen and methane, the optimal preparation condition was used for the preparation of series of Nd/TiO2 photocatalysts with various amounts of neodymium. All prepared photocatalysts were characterized by X-ray powder diffraction, N2 physisorption, Raman spectroscopy, transmission electron microscopy, UV–vis diffuse reflectance spectroscopy and photoelectrochemical measurements, respectively. The doping of TiO2 with neodymium can influence the particle size, the specific surface area, the value of band gap energy, the recombination of electron and hole and also the position of valence and conduction bands. Thus, the photocatalytic activity of the TiO2 photocatalyst for H2 evolution can be increased by optimum doping amount of neodymium. The presented and even more the future work is introducing not very common modification of TiO2 by neodymium prepared by unconventional method; the high pressure processing by hot water. Acknowledgements. The financial support of the Grant Agency of the Czech Republic (projects No. 17-20737S). This work was also financially supported by EU structural funding Operational Programme Research and Development for Innovation project No. CZ.1.05/2.1.00/19.0388.

Keywords: photocatalysis • hydrogen production • TiO2 • neodymium [1] [2]

M.R. Hoffmann, S.T.. Martin, W. Choi, D.W. Bahnemannt, Chem. Rev., 1995, 95, 69-96. J. Du, H. Chen, H. Yang, R. Sang, Y. Qian, Y. Li, G. Zhu, Y. Mao, W. He, D.J. Kang, Microporous Mesoporous Mater., 2013, 182, 87-94.

110

Wuhan, China

Poster Presentation PP43

Copper and Platinum Doped Titania for Photocatalytic Reduction of Carbon Dioxide Nela Ambrožová a, Martin Reli a, Marcel Šihor a, Miroslava Edelmannováa, Ivana Troppováa, Jaroslav Lang a, Anna Rokicińska c, Piotr Kuśtrowski c, Jeffrey C.S. Wu d, Kamila Kočí a,b* Address: aInstitute for Environmental Technology, bEnergy Units for Utilization of non Traditional Energy Sources, VŠB-Technical University of Ostrava, 17. listopadu 15, Ostrava-Poruba, Czech Republic c Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Kraków, Poland d Department of Chemical Engineering, National Taiwan University, Taipei 10617, Taiwan e-mail: ([email protected])

Abstract: Growing atmospheric level of carbon dioxide raises serious concerns about the

ensuing/resulting effects on the global climate. Heterogeneous photocatalysis is one of potential modern approaches for the mitigation of carbon dioxide emission resulting from human activities. The complex method of photocatalytic reduction of CO2 emissions in the presence of TiO2 can be done using previously published methods [1]. TiO2 still remains the most frequently applied semiconductor photocatalyst due to its availability, chemical stability, low cost, high photocatalytic activity and resistance to corrosion. Especially, photocatalytic reduction of CO 2 with H2O is important in the development of solar energy based on the carbon neutral cycle. There are several aspects, which influence the photocatalytic performance of nanoparticles such as the absorption edge energy, specific surface area and other structural properties and the most importantly electrons and holes energies. All these aspects can be significantly positively affected by modifying the TiO2 by Pt and/or Cu. Appropriate modification of the optical and electronic properties of TiO 2 can reduce the absorption edge energy it can also increase the lifetime of the photogenerated electrons and holes by effective charge carrier separation and decrease the electron–hole recombination rate. The correlation between the textural, optical and photoelectrochemical properties and the photocatalysts activity was a subject of this research. The parent TiO2, platinum and copper doped TiO2 photocatalysts with 0.5–2 wt. % of Pt, 0.5–2 wt. % Cu and 1 wt. % Pt combined with 1 wt. % Cu were prepared by using the sol-gel method followed by calcination at 500 °C for 5 hours in an atmosphere of technical air. All the prepared photocatalysts were tested for the CO2 photocatalytic reduction in a stirred batch reactor irradiated by 8W Hg lamp with maximum peak intensity at 254 nm. The main reaction product was methane; however, hydrogen and carbon monoxide were also detected. Products were analyzed in a highly sensitive gas chromatograph with a barrier discharge detector (BID). The textural, (micro)structural, optical and electronic properties of photocatalysts were characterized in detail by low-temperature nitrogen physisorption, X-ray powder diffraction, X-ray fluorescence, X-ray photon spectroscopy, scanning electron microscope, transmission electron microscope and diffuse reflectance UV-Vis spectroscopy. The photoelectrochemical characteristics of the photocatalysts were determined using a photoelectric spectrometer. The highest yields of CH4, H2 and CO were achieved in the presence of 2 wt. % Cu/TiO 2, 0.5 wt. % Cu/TiO2 and pure TiO2. It was suggested based on the conducted experiments that both the amount of chemisorbed oxygen or/and hydroxyl species on the TiO2 surface and specific surface area of photocatalyst highly influence the photocatalytic activity. Keywords: CO2 reduction • Photocatalysis • Titanium dioxide • XPS • OH-groups [1]

K. Koci, L. Obalova, Z. Lacny, Chem. Pap., 2015, 62, 1-9

111

Wuhan, China

Poster Presentation PP44

Unconventionally Prepared TiO2/g-C3N4 photocatalysts for Photocatalytic Decomposition of Nitrous Oxide Ivana Troppováa, Martina Šindlářová b, Marcel Šihor a, Martin Reli a, Michal Ritz b, Petr Praus a,b, Kamila Kočí a* Address: aInstitute for Environmental Technology, bFaculty of Metallurgy and Material Engineering, VŠB-Technical University of Ostrava, 17. listopadu 15, Ostrava-Poruba, Czech Republic e-mail: ([email protected])

Abstract: Nitrous oxide has been recognized as a contributor to the destruction of the ozone in the stratosphere. Moreover, N2O is the third most important of the long-lived greenhouse gases, accounting for 6.2% of the total global radiative forcing. N 2O decomposition into nitrogen and oxygen offers a simple solution for its conversion to natural components of air [1]. The photocatalytic decomposition of N2O under UV irradiation on photocatalysts (Eq. (1)) is one of the candidate methods for its removal as 1 N 2O hv ,catalyst  N 2  O2 ………………………………………………….. (1) 2

Graphitized carbon nitride (g-C3N4) has attracted a great attention due to its photocatalytic properties. G-C3N4 is a new type of non-metal semiconductor with outstanding mechanical, electrical, thermal, and optical properties. It has been used as a narrow band gap semiconductor for coupling with other semiconductors, e.g., ZnO and TiO2 [2]. A series of TiO2/g-C3N4 photocatalysts was prepared by a novel preparation approach, combining utilization of titanyl sulphate as a precursor for TiO2 with g-C3N4 nanosheets (CNs). The photocatalysts were successfully synthesized through unconventional pressurized water processing in a flow regime. TiO 2 was prepared by thermal hydrolysis from titanyl sulphate and g-C3N4 CNs were prepared from commercial melamine by thermal annealing at 620 °C and consequently at 500 °C to exfoliate bulk g-C3N4 into the CNs. TiO2/g-C3N4 photocatalysts with the various TiO2/g-C3N4 weight ratios from 1:1 to 1:3 were mechanically mixed, placed in a 10 mL high-temperature stainless steel cell and extracted/processed in a flow regime at pressure in the range of 10-13 MPa and temperatures of 200 °C using deionized water. The materials prepared under pressurized water were denoted as TiO2/g-C3N4 (1:1, 1:2, 1:3). The photocatalysts s were characterized by X-ray diffraction patterns, N2 physisorption, Raman spectroscopy, transmission electron microscopy, UV–vis diffuse reflectance spectroscopy and photoelectrochemical measurements, respectively. The photocatalytic activity of the developed materials was examined for the photocatalytic decomposition of N 2O, which was performed in a stainless-steel batch reactor illuminated with an 8 W Hg lamp with 365 nm wavelength. The correlation between micro/structural, optical and electrochemical properties of TiO2/g-C3N4 photocatalysts and their photo-induced efficiency for removal of nitrous oxide in gas phase was investigated. The presented work shows a new method to fabricate TiO2/g-C3N4 photocatalysts and clearly revealed that the introduction of TiO2 is a new and innovative approach to improve the photocurrent and photopotential efficiencies of g-C3N4. Acknowledgements. The financial support o fthe Grant Agency of the Czech Republic (projects No. 16-10527S). This work was also financially supported by EU structural funding Operational Programme Research and Development for Innovation project No. CZ.1.05/2.1.00/19.0388.

Keywords: g-C3N4 • Titanium dioxide • Pressurized water processing • Photocatalysis • Decomposition of N2 O [1] [2]

R.d.Richter, S. Caillol, J. Photochem. Photobiol. C: Photochem. Rev. 12 (2011) 1. X. Song, Y. Hu, M. Zheng, C. Wei, Applied Catalysis B: Environmental 182 (2016) 587.

112

Wuhan, China

Poster Presentation PP45

Microwave-assisted Hydrothermal Synthesis of Anatase TiO2 Single Crystals Exposing High-Percentage {001} Active Facets and Their Photocatalytic Properties Huifen Tong, Gang Chang, Pai Li, and Yunbin He* Faculty of Materials Science & Engineering, Hubei University, Wuhan 430062, China [email protected]

Abstract: Different facets of anatase TiO2 crystal exhibit distinctive physical and chemical properties [1]. Through applying specific capping agents and synthesis techniques, high-energy {001} active facts can be dominantly exposed and stabilized on the surface of anatase TiO 2 [2], which can greatly enhance the photocatalytic activity of anatase TiO 2. In this work, fast microwave-assisted technique [3] was applied to prepare anatase single crystals using tetrabutyl titanate [Ti(OBu)4] as the Ti precursor and HF or NaF as capping agent at 210 °C. Herein, anatase TiO2 single crystals with dominant {001} facets were obtained by changing the reaction time and the content of capping agent. The morphology, composition and structure of the as-obtained crystals were characterized using Scanning Electron Microscopy equipped with Energy Dispersive X-ray Analysis and X-ray Diffraction. The results showed that anatase single crystals with a truncated bipyramid shape were obtained as shown in Figure 1 with the synergistic effect of H+ and F-. Additionally, the size of the TiO2 crystals increased with extending synthesis time while the percentage of {001} facets in individual crystals stayed nearly unchanged. The photocatalytic activities of the TiO2 crystals were studied by decomposition of the methylene blue. In addition, the influence of the percentage of {001} facets and the size of TiO 2 crystals on the photocatalytic activity was investigated as well through the comparison of the decomposition results.

Figure.1 Anatase TiO2 crystals with a truncated bipyramid shape Acknowledgement. This work was financially supported by the National Natural Science Foundation of China (No. 51572073). Keywords: Microwave • anatase TiO2 • {001} facets• photocatalyst [1] Liu, Yu, Jaroniec, Chem. Mater., 2011, 23, 4085-4093 [2] Wen, Jiang, Qiao, Yang, Lu, J. Mater. Chem., 2011, 21, 7052-7061 [3] Zhang, Li, Yang, Yu, Chem. Commun., 2009, 29, 4381-4383

113

Wuhan, China

Poster Presentation PP46

Enhanced performances of dye-sensitized solar cells based on Au/Aghybrid TiO2 plasmonic nanocomposites Huili Ran a,b, Mengjun Ma a,b, Jiajie Fan a,b*, Guosheng Shao a,b Address: a School of Materials Science and Engineering, Zhengzhou University, Zhengzhou, China. b International Centre for Designer Low-Carbon and Environmental Materials, Zhengzhou University, Zhengzhou, China. e-mail: [email protected]

-2

Photocurrent (mA cm )

Abstract: Dye-sensitized solar cells (DSSCs) were fabricated using commercial TiO 2 with a small particle size as bonding underlayer and hybrid noble metal (Au and Ag) nanoparticle (NP) and nanowire (NW) incorporated TiO2 composites, consisting of 3 dimensional (3D) microspheres, 3D hollow spheres, 2 dimensional (2D) nanosheets and commercial P25, as multifunctional light scattering overlayer. The influence of Au NP, Ag NP, Au NW and Ag NW on of microstructures of the photoanodes and the performance of DSSCs was investigated. The results demonstrated that the range and strength of light absorption of TiO2 photoanodes, the photo capture ability of dye, and power conversion efficiency of the cells were all increased significantly by the advantage of the plasmonic effect. Under optical conditions, a power conversion efficiency () of 5.74% and a short circuit photocurrent density (Isc) of 13.02 mAcm2 was obtained in the TiO2-Ag NW DSSC, representing a 25.3% increase in the conversion efficiency compared to the reference solar cell based on the pure TiO2 film (4.58%, 11.83 mAcm2). The enhancement of Isc and η were ascribed to a combination of two factors: (i) improved electron transport properties of Ag NW; (ii) a further improvement of light absorption caused by the local surface plasmon resonance effect and the possible enhanced light scattering of AgNW in the photoanode. Pure TiO2

10

TiO2-Au NP TiO2-Ag NP

8

TiO2-Au NW TiO2-Ag NW

6 4 2 0 0.0

0.2

0.4

0.6

0.8

Voltage (V) Fig. 1 I-V characteristics of DSSCs made from pure TiO2, TiO2-Au NP, TiO2-Ag NP, TiO2-Au NW and TiO2-Ag NW film electrodes. Acknowledgements: This work was supported by the National Natural Science Foundation of China (51402263 and U1304514). Keywords: Plasmonic nanocomposites • Dye-sensitized solar cells (DSSCs) • Au • Ag • Hybrid TiO2 [1] J. Xu, G.X. Wang, J.J. Fan, et al., J. Power Sources, 2015, 274, 77-84. [2] J.J. Fan, Z.Z. Li, W.Y. Zhou, et al., Appl. Surf. Sci., 2014, 319, 75-82.

114

Wuhan, China

Poster Presentation PP47

Numerical investigation of CuO based heterojunction solar cells Kemeng Tong a,b, Jinsheng Zhai a,b, Jiajie Fan a,b*, Guosheng Shao a,b Address: a School of Materials Science and Engineering, Zhengzhou University, Zhengzhou, China. b International Centre for Designer Low-Carbon and Environmental Materials, Zhengzhou University, Zhengzhou, China. e-mail: [email protected]

Abstract: Metal oxide (MO) semiconductors hold the promise for the development of sustainable

and green solar cells with high efficiency, especially the cuprous (Cu2O) and the cupric (CuO) oxides, act as optical absorber in photovoltaic (PV) cells owing to their low-cost and being nontoxic and abundant in resources. This paper highlights a numerical investigation on MO solar cells using CuO as the optical absorber layer. By replacing n/p-Si thin films with appropriate compound semiconductors (n-type TiO2, ZnO, SnO2, Ga2O3 and p-type Cu2O, respectively), a wxAMPS (Analysis of Microelectronic and Photonic Structures) software numerical modeling was used to explore the effects of these materials on the performance of solar cells. The influence of the thickness of CuO layer on the performance of photovoltaic solar cells was investigated, and the optimization was carried out to obtain the best performance. Furthermore, the temperature stability of the cells is modeled. In the ideal case, heterojunction solar cell consists of n-Ga2O3, p-CuO, and p+-Cu2O represented a high conversion efficiency of 32.38%. The research can provide theoretical basis for the materials of oxide as photovoltaic cells. 40

35

Ga2O3

Efficiency (%)

30

Efficiency (%)

TiO2

Ga2O3 SnO2 ZnO TiO2

25

n-Si

20

15

35

SnO2 ZnO n-Si

30

25

20 0

1

2

3

4

5

6

7

CuO-layer thickness (m)

8

9

-40

-20

0

20

40

60

80

100

Temperature ( C) o

Fig. 1 Modeled I-V characteristics of solar cells based on different n-type semiconductors

Fig. 2 Modeled I-V characteristics of temperature dependent solar cells

Acknowledgements: This work was supported by the National Natural Science Foundation of China (51402263 and U1304514). Keywords: CuO • Heterojunction solar cells • wxAMPS • Temperature stability • Modeling [1] Z.Z. Li, K.M. Tong, R.S. Shi, et al., J. Alloy. Compd., 2017, 695, 3116-3123. [2] J.J. Fan, Z.Z. Li, W.Y. Zhou, et al., Appl. Surf. Sci., 2014, 319, 75-82. [3] L. Zhu, G.S. Shao, J.K. Luo, Semicond. Sci. Technol., 2013, 28, 055004 (10pp). [4] L. Zhu, G.S. Shao, J.K. Luo, Solid State Sci., 2012, 14, 857-863. [5] L Zhu, G.S. Shao, J. K. Luo, Semicond. Sci. Technol., 2011, 26, 085026 (9pp)

115

120

Wuhan, China

Poster Presentation PP48

Effects of post-annealing on structural, photoluminescence, optical, and electrical properties of CuO thin films Zhenzhen Li a,b, Jiajie Fan a,b*, Guosheng Shao a,b* Address: a School of Materials Science and Engineering, Zhengzhou University, Zhengzhou, China. b International Centre for Designer Low-Carbon and Environmental Materials, Zhengzhou University, Zhengzhou, China. e-mail: [email protected], [email protected]

Abstract: CuO thin films were grown on glass substrates at room temperature a novel remote plasma sputtering technique from a high purity Cu target. And then, effects of rapid post-annealing treatments at various temperatures in air ambient on CuO thin film were investigated systemically. The properties of the films are characterized by X-ray diffraction (XRD), Raman spectroscopy, field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), energy dispersive spectroscopy (EDS), UV-vis-near infrared absorption spectroscopy, and Hall measurements. In the whole annealing temperature range (≤ 450 oC), no reduction from CuO to Cu2O are observed and the films remain single-phased. The post-annealing is found to be effective on the distribution of grains and their sizes, which is a very useful method to improve the optical/electrical properties of thin films. Annealing in air enhances the transmittance in the visible region due to the decrease of the defect scattering. Moreover, the optical band gap of CuO thin films is enlarged from 1.10 to 1.37 eV with increasing annealing temperature. The increase of optical band gap accompanying the reduction of Urbach energy indicates that the widening of optical band gap may result from the partial elimination of defect band tail after thermal annealing in air. The prospect of copper-oxide thin films based solar cells has to be proved by significant progress at its physical properties to be further investigated and enhanced.

Transmittance (%)

60 50 40 30 20 10 0

400

600

800

1000

1200

4 2.0 3 1.5 2 1.0

Hall mobility (cm-2.V-1.S-1)

70

2.5

as deposited 250 350 450

Carrier concentration (cm-3)

80

1

1400

100 200 300 400 post-annealing temperature ()

Wavelength (nm)

Fig. 1 Transmittance of the annealed CuO films

Fig. 2 Carry concentration and hall mobility

Acknowledgements: This work was supported by the National Natural Science Foundation of China (51402263 and U1304514).

Keywords: CuO thin films • Remote plasma sputtering • Post-annealing • Optoelectronic properties [1] Z.Z. Li, K.M. Tong, R.S. Shi, et al., J. Alloy. Compd., 2017, 695, 3116-3123. [2] J.J. Fan, Z.Z. Li, W.Y. Zhou, et al., Appl. Surf. Sci., 2014, 319, 75-82.

116

Wuhan, China

Poster Presentation PP49

Black phosphorus/TiO2 composite photoanode with enhanced photoelectrical performance Jia Song 1, Jing Wang 1*, Xiaoyu Lin 1, Jingfu He 1, Hualei Liu1, Yongpeng Lei *2, Zengyong Chu 1 2

1 College of Science, National University of Defense Technology, Changsha, Hunan, China College of Basic Education, National University of Defense Technology, Changsha, Hunan, China e-mail: [email protected] (Jing Wang), [email protected] (Yongpeng Lei)

Abstract: Black phosphorus (BP) shows broad application in optical/photoelectric and semiconductor fields. Here, different thickness exfoliated BP nanosheets were obtained by solvent ultrasonication exfoliation method. The structure and morphological of the samples were investigated by XRD, SEM and AFM. The absorption spectra and fluorescence spectra of the samples were measured. Dye-sensitized solar cells (DSSCs) base on BP nanosheets/TiO2 composite film as working electrodes were fabricated. The performance of solar cells were studied by I-V, incident photon-to-current conversion efficiency (IPCE) and electrochemical impedance spectroscopy (EIS) measurements. The results show that the light absorption ability of BP depends on its layer numbers and phosphorene can absorb ultravioletlight (260~325nm) specifically. The decrease of interfacial transport resistance and the increase of the utilization of sunlight favor the enhanced photoelectric conversion (η) of ~38%. The stability of BP nano-sheets was also studied and the decrease of the corresponding η is mainly due to the defects caused by chemical etching and thus impeded electron transport. In all, there is good reason to believe that phosphorene can be an excellent candidate in DSSCs, photoelectric detection, field effect transistor and so on.

Keywords: Black phosphorus • Solvent exfoliation • Ultraviolet absorption • DSSCs • Stability [1] Y. Shao, J. Wang, H. Wu, et al. Electroanal., 2010, 22(10): 1027-1036 [2] Y. Zhou, Y. Lei, D. Wang, et al. Chem. Comm., 2015, 51(68): 13305-13308 [3] T. Mueller, F. Xia, P. Avouris. Nature Photon., 2010, 4(5): 297-301 [4] J. Kang, J. D.Wood, S. A.Wells, et al. ACS Nano, 2015, 9(4): 3596-3604 [5] D.Hanlon, C.Backes,E. Doherty, et al. Phys., 2015, 6: 8563-8574 [6] Y. Poya, K. Bijra, F. Tara, et al. Adv. Mater., 2015, 27(11): 1887-1892 [7] J. R. Brent, N. Savjani, E. A. Lewis, et al. Chem. Comm., 2014, 50(87): 13338-13341

117

Wuhan, China

Poster Presentation PP50

Incorporation of oxide into graphene and g-C3N4 for enhanced photocatalytic activity Jiaqian Qin a,b*, Chengwu Yang b, Xinyu Zhang b a

Metallurgy and Materials Science Research Institute, Chulalongkorn University, Bangkok 10330, Thailand State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004, P. R. China e-mail: [email protected]

b

Abstract: Graphene is an atomically thin layer of carbon atoms arranged in a honeycomb structure. Graphene has unique electrical properties, and acts as an excellent conductor. Meanwhile, GO is also possesses the similar properties to graphene as well as the special surface structures with introduced hydroxyl ad carboxyl groups, which is benefit for the preparation of rGO-containing nanocomposites. The graphitic carbon nitride (g-C3N4) has also become a new research hotspot and drawn broad interdisciplinary attention as a metal-free and visible-light-responsive photocatalyst in the arena of solar energy conversion and environmental remediation. To further improve the photocatalytic performance, the ZnO-GO[1], ZnO-rGO[2], ZnO-gC3N4[3] and TiO2-gC3N4 [4]nanocomposites were developed in our group. (1) We developed a facile room temperature route to synthesize ZnO–GO nanocomposites using the colloidal coagulation effect. This method concurred with “green” chemistry as it was simple and environmentally friendly. As GO incorporated into ZnO nanorods, the prepared nanocomposites have superior adsorption capacity and enhanced photocatalytic performance[1]. (2) ZnO microspheres-rGO composites (microspheres, ∼1–3 μm, ZnO nanorod, diameter ∼30 nm) were successfully synthesized via a facile solution method. SEM results indicate that the ZnO microspheres anchored on the surface of rGO sheets. In this study, ZnO microspheres-rGO composite (4.06 wt.% GO) shows superior phtoodegradation activity of MB under UV light irradiation in comparison with the other content of rGO composites, pure ZnO microspheres, and P25 TiO2[2]. (3) The 2D sheet-like carbon-doped ZnO/g-C3N4 nanocomposites were successfully synthesized. The obtained sheet-like carbon-doped ZnO/g-C3N4 nanocomposites exhibit the enhanced photodegradation efficiency for MB than pure ZnO, g-C3N4, and P25 TiO2[3]. (4) The carbon-doped porous TiO2 was successfully growth on the TiC surface via a facile method of oxidizing TiC under air atmosphere. The as-prepared TiC@C-TiO2 materials show a stable and efficient reaction activity for photocatalytic generated hydrogen. A maximum amount of photogenerated hydrogen of TC2 is up to 558.46 μmol/g, which is higher than those of C-TiO2 and P25[5]. Furthermore, The TiO2-gC3N4 nanocomposites can be prepared by one-step facile method. The prepared nanocomposites have good photocatalytic H2 production under visible light irradiation[4]. Keywords: Graphene • Graphene oxide • g-C3N4 • ZnO • TiO2 [1] J. Qin, X. Zhang, Y. Xue, N. Kittiwattanothai, P. Kongsittikul, N. Rodthongkum, S. Limpanart, M. Ma, R. Liu, Appl. Surf. Sci., 2014, 321, 226-32 [2] J. Qin, X. Zhang, C. Yang, M. Cao, M. Ma, R. Liu, Appl. Surf. Sci., 2017, 392, 196-203 [3] J. Qin, C. Yang, M. Cao, X. Zhang, S. Rajendran, S. Limpanart, M. Ma, R. Liu, Mater. Lett., 2017, 189, 156-59 [4] C. Yang, J. Qin, X. Zhang, 2017, submitted, [5] C. Yang, X. Zhang, J. Qin, X. Shen, R. Yu, M. Ma, R. Liu, J. Catal., 2017, 347, 36-44

118

Wuhan, China

Poster Presentation PP51

Copper Nanoparticles Interspersed MoS2 Nanoflowers with Enhanced Efficiency for CO2 Electrochemical Reduction to Fuel Guodong Shi, Ying Yu* Address: Institute of Nanoscience and Nanotechnology, College of Physical Science and Technology, Central China Normal University, Wuhan 430079, China e-mail: [email protected]

Abstract: Electrocatalytic conversion of carbon dioxide (CO2) has been considered as an ideal way to simultaneously solve the energy crisis and environmental issue around the world. In this work, ultrasmall Cu nanoparticles interspersed flower-like MoS2 was successfully fabricated via a facile microwave hydrothermal method. The designed optimal hierarchical Cu/MoS 2 composite not only exhibited remarkably enhanced electronic conductivity and specific surface area but also possessed improved CO2 adsorption capacity, resulting in a significant increase in overall faradaic efficiency and a 7-fold augment for the faradaic efficiency of CH4 in comparison with bare MoS2. In addition, the Cu/MoS2 composite had a superior stability with high efficiency retaining for 48 h in electrochemical process. It is anticipated that the designed Cu/MoS 2 composite electrocatalyst may provide new insights for transition metal sulfides and non-noble particles applied to CO2 reduction.

Keywords: ultrasmall Cu; MoS2; electrochemical; stability [1] G. Shi, L. Yu, X. Ba, X. Zhang, J. Zhou and Y. Yu, Dalton Trans., 2017, DOI: 10.1039/C6DT04381J.

119

Wuhan, China

Poster Presentation PP52

Exploring the structure of the polymeric g-C3N4 via the nanoribbon** Hong-Zhang Wu*, and Zhenling Wang* The Key Laboratory of Rare Earth Functional Materials and Applications, Zhoukou Normal University, Zhoukou 466001, China e-mail: [email protected]; [email protected]

Abstract: The optical properties and condensation degree of polymeric g-C3N4 show a strong dependence on the process temperature1-3. For polymeric g-C3N4, its structure and condensation degree depend on the structure of strand (structural unit). Here, on the basis of the strand of polymeric g-C3N4 as a fully condensed nanoribbon, the width of nanoribbon would be closely related to the condensation degree. Then, the structure of the polymeric g-C3N4 is explored via the proposed nanoribbon employing first-principle density functional theory. The calculations show that the width of fully condensed nanoribbon has a significant effect on the electronic structure of polymeric g-C3N4 nanoribbon, which is the indirect evidence that the electronic structure depends on the structure of polymeric g-C3N4. The role of hydrogen bond is evaluated by the formation energy of polymeric g-C3N4 nanoribbon. The edge shape also has a distinct effect on the electronic structure of polymeric g-C3N4 nanoribbon. Furthermore, conductive band minimum and valence band maximum of polymeric g-C3N4 nanoribbon show a strong localization, which in good agreement with the quasi-monomer characters. These results provide new insight on the relationship between the structure and electronic structure of the polymeric g-C3N4 and the properties of polymeric g-C3N4 nanoribbon.

Keywords: polymeric g-C3N4 nanoribbon • condensation degree • electronic structure • edge shape [1] [2] [3]

Tyborski, T.; Merschjann, C.; Orthmann, S.; Yang, F.; Lux-Steiner, M. C.; Th, S.-N., J. Phys.: Condens. Matter. 2012, 24, 162201. Merschjann, C.; Tyborski, T.; Orthmann, S.; Yang, F.; Schwarzburg, K.; Lublow, M.; Lux-Steiner, M. C.; Schedel-Niedrig, T., Phys. Rev. B 2013, 87, 205204. Tyborski, T.; Merschjann, C.; Orthmann, S.; Yang, F.; Lux-Steiner, M. C.; Th, S.-N., J. Phys.: Condens. Matter. 2013, 25, 395402.

120

Wuhan, China

Poster Presentation PP53

Preparation and Application of g-C3N4 -NiO -Co3O4 Hybrid Nanocomposites with an Effective Photoelectrochemical Property for Analysis of Tetrabromobisphenol-A Yi Liu, Jing Zou* , Wanyun Gong, Sheng Zhang, Xin Zhou , Yanjuan Sun , Shengli Wu School of Chemistry and Environmental Engineering, Key Laboratory for Green Chemical Process of Ministry of Education, Wuhan Institute of Technology, Wuhan 430205, P.R. China. Email: [email protected]

Abstract: The electrocatalytic activity of nitrogen carbon-based nanocomposites catalysts for oxygen reduction reaction (ORR) is improved by doping transition metal. NiO and Co 3O4 transition metal compounds co-doping g-C3N4 nanocomposites were prepared by one step thermal decomposition process with NiCl2·6H2O, Co(NO3)2·6H2O and melamine. The photoelectrochemical behaviors of the resulting hybrid nanocomposites have been compared with undoped g-C3N4. Its photocurrent density and donor density were about 2.4 and 7.5 times as much as that of undoped gC3N4, respectively. Based on its excellent photoelectrochemical property, a simple and effective photoelectrochemical method for sensitive detection of Tetrabromobisphenol-A (TBBP-A) was developed with differential pulse voltammetry under visible light irradiation. Under optimum conditions, NiO/Co3O4/g-C3N4/GCE exhibited excellent differential pulse voltammetry response depending on the concentration of TBBP-A. Two linear ranges were gotten from 0.3 to 10 μmol L–1 and 10 to 500 μmol L–1. The detection limit of 0.1 μmol L–1 (S/N=3) was found. This photoelectrochemical method displayed good reproducibility, high stability, and was successfully used to the determination of TBBP-A in real water samples, suggesting that this method is an efficient and convenient, offering great potential for construction of photoelectrochemical method toward toxic substances. Keywords: NiO/Co3O4/g-C3N4 nanocomposites • photoelectrochemical method• tetrabromobisphenol-A • toxic substances [1] M.A.-E. Abdallah, S. Harrad, A. Covaci, Environ. Sci. Technol, 2008, 42, 6855-6861. [2] E. Blanco, M.C. Casais, M.C. Mejuto, R. Cela, Anal. Chem., 2006, 78, 2772-2778. [3] S. Chu, G.D. Haffner, R.J. Letcher, J. Chromatogr. A, 2005, 1097, 25-32. [4] Z. Zhou, Y. Shen, Y. Li, A. Liu, S. Liu, Y. Zhang, ACS Nano, 2015, 9, 12480-12487. [5] D. Chen, H. Zhang, Y. Liu, J. Li, Energy Environ. Sci., 2013, 6, 1362-1387. [6] F. Zhao, H. Cheng, Y. Hu, L. Song, Z. Zhang, L. Jiang, L. Qu, Sci. Rep., 2014, 4, 5882. [7] Z. Cai, M. Rong, T. Zhao, L. Zhao, Y. Wang, X. Chen, J. Electroanal. Chem., 2015, 759, 32-37. [8] J. Zhuang, W. Lai, M. Xu, Q. Zhou, D. Tang, ACS Appl. Mater. Interfaces, 2015, 7, 8330-8338. [9] Y. Hou, Z. Wen, S. Cui, X. Guo, J. Chen, Adv. Mater., 2013, 25, 6291-6297. [10] F. Qi, Y. Li, Y. Wang, Y. Wang, S. Liu, X. Zhao, RSC Adv., 2016, 6, 81378-81385.

121

Wuhan, China

Poster Presentation PP54

2D Clay/rGO Ordered Heterostructures Dispersible in Water Via a One-Step Green Route E.C. Vermisoglou1, T. Giannakopoulou1, N. Todorova1, T. Vaimakis2, D. Petridis1, C. Trapalis1* 1

Institute of Nanoscience and Nanotechnology (INN), NCSR “Demokritos”, Agia Paraskevi, 15341, Attikis, Greece 2 Department of Chemistry, University of Ioannina, 45110 Ioannina, Greece *Corresponding author: [email protected],gr

Abstract: A major challenge in the chemistry of carbon refers to the exfoliation of graphite in aqueous or organic media in order to obtain discrete graphene sheets [1-3]. This challenge of liquid exfoliation of graphite has not been yet satisfactorily overcome, in spite of some progress achieved in the exfoliation of graphite in certain organic solvents or aqueous media in presence of surfactant or polymeric stabilizers [4,5] producing however graphene sheets in relatively small yields. In this study, a facile and green method for trapping the hydrophobic reduced graphene oxide (rGO) between the hydrophilic Kunipia F (KF) layers in order to attain stable aqueous dispersions of rGO is described. Initially stable aqueous dispersions of hydrophilic clay intercalated with hydrophilic graphene oxide (GO) sheets were formed providing well-organized heterostructures (KF/GO), as it was revealed by SEM images. These structures were preserved in the product obtained after hydrothermal treatment of KF/GO, i.e. KF/rGO, where the hydrophilic GO was converted to hydrophobic rGO. UV measurements revealed the aforementioned conversion which was accompanied by a characteristic change in color from yellow-brown to black in the corresponding aqueous dispersions of KF/GO and KF/rGO hybrids. The stability of these homogeneous dispersions was confirmed by Zeta Potential measurements implying interactions both in cases of GO and rGO with clay sheets that made feasible the effective interstratification of graphene-clay layered materials. In these stable dispersions chemistry in aqueous environment could be fully utilized making possible their incorporation e.g. as fillers to hydrophilic polymeric matrices extending thus the limits of application.

Keywords: reduced graphene oxide • clay • heterostructure • hydrothermal • Kunipia F [1] Y. Liang, D. Wu, X. Feng, K. Müllen, Adv.Mater., 2009, 21 1679-1683. [2] D. Li, M. B. Müller, S. Gilje, R. B. Kaner, G. G. Wallace, Nat. Nanotechnol. , 2008, 3, 101-105. [3] J. Zhu, New solutions to a new problem, Nat. Nanotechnol. , 2008, 3, 528-529. [4] Y. Hernandez, V. Nicolosi, M. Lotya, F. M. Blighe, Z. Sun, S. De, I. T. McGovern, B. Holland, M. Byrne, Y. K. Gun’ko, J. J. Boland, P. Niraj, G. Duesberg, S. Krishnamurthy, R. Goodhue, J. Hutchison, V. Scardaci, A. C. Ferrari, J. N. Coleman, Nat. Nanotechnol., 2008, 3, 563-568. [5] S.-Z. Zu, B. H. Han, J. Phys. Chem. C, 2009, 113, 13651-13657.

122

Wuhan, China

Poster Presentation PP55

Graphene and g-C3N4 based photocatalysts for NO Oxidation: A Review Aspasia Nikokavoura and Christos Trapalis * Institute of Nanoscience & Nanotechnology, NCSR “Demokritos”, Agia Paraskevi, 15341, Attikis, Greece e-mail:[email protected]

Abstract: NOx liberated into atmosphere from automobile exhausts and fossil fuel combustion, comprise the major air pollutants. They are responsible for serious environmental problems such as acid rain, ozone accumulation, haze and photochemical smog. Besides they contribute to the deterioration of human health by causing decrease of the lung function and respiratory problems. The application of photocatalytic methods in order to mitigate the presence of NO x in the atmosphere is preferable as they are environmentally friendly, mild and low cost [1]. NOx oxidation to non volatile nitrates on the surface of graphene and g-C3N4 based photocatalysts has attracted much interest during the last years due to their 2D structures with large specific surface area, thermal and chemical stability and enhanced visible light utilization. Therefore, in this review, the photocatalytic activity of g-C3N4, g-C3N4 composites and graphene based composites towards NOx removal was studied. g-C3N4 and g-C3N4 based composites: g-C3N4 nanosheets, have been used for the NOx oxidation, such as those synthesized by pyrolysis of urea or thiouria. They exhibited high photocatalytic activity owing to the enhanced crystallinity, reduced layer thickness, large surface area and pore volume and enlarged band gap. The increased photocatalytic activity of Bi or Ag doped g-C3N4, was attributed to the surface plasmon resonance (SPR) which increases the visible light harvesting and the charge separation [2]. Coupling of g-C3N4 with TiO2 or N/TiO2 resulted in the improvement of the photocatalytic performance through reduction of the recombination of the photogenerated electrons and holes [1]. g-C3N4/g-C3N4, Bi2O2CO3 /g-C3N4, BiOBr/g-C3N4, BiVO4/g-C3N4, CeO2/gC3N4 heterojunctions photocatalysed effectively the NOx decomposition due to the well matched band structures and the formation of intimate interactions [3-4]. graphene based composites: The intimate and strong interfacial interaction between the components in TiO2/GR, TiO2/GO, TiO2/RGO, BiOIO3/RGO, BiOBr/GR, N/(BiO)2CO3/GR and N/(BiO)2CO3/GO composites, contributes to an enhanced photocatalytic activity [5-6]. Besides, the electron trapping by graphene which favors the formation of radicals (O 2.- and OH. ) participating in the mechanism and the excellent conductivity of graphene which suppresses the recombination of photogenerated electrons and holes, contribute to the enhancement of the photocatalytic efficiency. The combination of g-C3N4 and graphene was proved to be successful as g-C3N4/GR and gC3N4/RGO composites additionally exhibited increased surface area and pore volume and improved visible light utilization [7]. In conclusion, the continuing research in the field of graphene and g-C3N4 based photocatalysts for the NOx oxidation is very promising due to the effectiveness, low preparation cost, reduced toxicity and easy modification of these materials. Keywords: photocatalysis • gC3N4 • graphene • NOx removal • heterojunctions [1] I. Papailias, N. Todorova, J. Yu, D. Dimotikali, C. Trapalis, Catal. Today, 2016, (doi: org/10.1016/j.cattod.2016.06.032) [2] Y. Sun, T. Xiong, Z. Ni, J. Liu, F. Dong, W. Zhang, W.-K. Ho, Appl. Surf. Sci., 2015, (doi: org/10.1016/j.apsusc.2015.07.071) [3] F. Dong, Z. Zhao, T. Xiong, Z. Ni, W. Zhang, Y. Sun, W-K. Ho, ACS Appl. Mater. Interfaces, 2013, 5, 11392-11401 [4] Y. Sun, W. Zhang, T. Xiong, Z. Zhao, F. Dong, R. Wang, W-K. Ho, J. Colloid Interface Sci., 2014, 418, 317-323 [5] T. Xiong, F. Dong, Y. Zhou, M. Fu, W-K. Ho, J. Colloid Interface Sci., 2015, 44, 16-24 [6] Y. Wang, S. Zhang, Y. Zeng, M. Ou, Q. Zhong, J. Mol. Catal. A: Chem., 2016, 423, 339-346 [7] Y. Li, Y. Sun, F. Dong, W-K. Ho, J. Colloid Interface Sci., 2014, 436, 29-36

123

Wuhan, China

Poster Presentation PP56

Photoreduction of Electrochemically Deposited Graphene Films: Solar vs UV and Pre- vs Post-photoreduction Tatiana Giannakopoulou, Nadia Todorova and Christos Trapalis* Institute of Nanoscience and Nanotechnology, NCSR “Demokritos”, Agia Paraskevi, Attikis, 15341, Greece *Corresponding author: [email protected]

Introduction: Easily scalable and employing no hazardous chemicals, electrochemical deposition (ECD) of graphene films [1] attracts much attention especially in graphene electrode materials for solar cell [1, 2] and supercapacitors [1, 3]. The ECD of graphene films is possible from graphene oxide (GO) suspensions due to presence of the oxygen-containing groups on its surface. These groups endow the GO flakes with hydrophilic properties and therefore contribute to creation of stable aqueous suspensions. Also, they promote charging of the GO flakes either via direct deprotonation of carboxylic groups in water or via possibility of surface functionalization. But, these groups reduce carriers’ mobility in GO films making chemical reduction mandatory. Yet, the process usually requires toxic reducing agents [4] stimulating search for green reducing processes [5]. In the present work, two-step preparation of graphene films on conductive ITO substrate was proposed using ECD from GO suspensions making emphasis on green pre- and post-deposition reduction via solar and UV irradiation which to our knowledge is used for this purpose in similar deposition procedures for the first time. Experimental: GO synthesized via modified Hummer’s method was used to prepare aqueous suspensions. The GO films were deposited on ITO substrate under application of constant electrical potential (+ 4 V) and controlling deposition time by Metrohm Autolab PGSTAT302 potentiometer. Three-electrode electrochemical cell with ITO, Ag/AgCl and Pt plate was employed as working, reference and counter electrodes, correspondingly. Solar light was simulated using SUNTEST instrument equipped with Xenon lamp and irradiance of 765 W/m2 while UV illumination was performed using Philips BL Actinic 40 W lamp with irradiance of 10 W/m2. The illumination of aqueous GO suspensions prior to deposition process or GO films after deposition provided pre- or post-deposition reduction steps. The structural changes in GO suspensions and films were investigated using the X-ray diffraction analysis (XRD), UV-visible and Raman spectroscopy. The X-ray photoelectron spectroscopy (XPS) was employed to determine the films’ surface chemical composition and bonding while cyclic voltammetry (CV) and electrochemical impedance spectroscopy were used to estimate films’ capacitance and conductivity. Results and discussion: According to the XRD results, the intensity of the main peak (002) decreased and shifted to higher 2θ values after the pre- and post-deposition irradiation evidencing the GO photoreduction. For solar light irradiation, the peak shift was almost the same in the post- and pre-irradiated films with essential peak intensity decrease for the latter . For UV irradiation, larger peak shift was observed in the postirradiated than in the pre-irradiated films. The GO reduction was optically observed by darkening of GO suspensions. The effect was more pronounced for solar irradiation that was confirmed by the disappearance and shift of the characteristic peaks of electronic transitions in the C=O and C-C bonds in the UV-visible spectra (Fig. 1). According to the Raman analysis, the ratio ID/IG = 0.88 remained almost unchanged in irradiated and non-irradiated films. This was connected to the preservation of imperfections in GO network after solar and UV irradiation.

124

Wuhan, China

GO dispersions after UV irradiation

GO dispersions after solar irradiation 3,0

3,0

1,5 1,0

300

2,0

GOin GO16UV GO32UV GO48UV

C=O

230

C-C 2,5

Absorbtion, a.u.

300

230 252

Absorption, a.u.

2,5

GOin GO16S GO32S GO48S

C=O

C-C

2,0 1,5 1,0 0,5

0,5 0,0 200

250

300

350

400

450

500

550

0,0 200

600

250

300

350

400

450

500

550

600

Wavelength, nm

Wavelength, nm

(b)

(a)

Fig. 1. UV-visible spectra of GO dispersions for different irradiation time: after irradiation with solar (a) and UV (b) light. The results from the XPS analysis (Fig. 2) revealed that upon photoreduction the oxygen containing functional groups are removed since content of the C in C-O bonds in relation to that of sp2 C and sp3 C (C=C and C-C bonds) is decreased. GOin

GO48Spost

GO48UVpost

C-C,C=C

Intensity, a.u.

Intensity, a.u.

Intensity, a.u.

C-O, C-O-C

O-C=O

294

292

290

288

286

284

Binding energy, eV

(a)

282

280

294

292

290

288

286

284

282

280

294

Binding energy, eV

(b)

292

290

288

286

284

282

280

Binding energy, eV

(c)

Fig. 2. XPS of initial GO film (a) and after irradiation with solar (b) and UV (c) light for 48 h of postdeposited films. Notable enlargement of CV loop area and the reduction of equivalent in-series resistance was observed in solar pre- and post-irradiated as well as in UV post-irradiated films with increase of the irradiation time. This can originate from the enhancement of the films’ specific surface area and conductivity. Conclusions: Environmental and human friendly ECD and reduction method for fabrication of graphene films was followed. Solar and UV irradiation before and after the deposition procedure for reduction purposes were comparatively investigated. More effective reduction using solar than UV irradiation was observed in pre-irradiated films. However, the GO reduction in post-irradiated films was practically comparable for UV and solar irradiation that was confirmed by XRD, XPS, cyclic voltammetry and electrochemical impedance spectroscopy. Keywords: graphene films • electrochemical deposition• solar • UV • photoreduction [1] A. Chavez-Valdez, M.S. Shaffer, A.R. Boccaccini, J. Phys. Chem. B, 2013, 117, 1502-1515 [2] H. Choi, H. Kim, S. Hwang, Y. Han, M. Jeon, J. Mater. Chem., 2011, 21, 7548-7551. [3] Y.S. Lim, H.N. Lim, S.P. Lim, N.M. Huang, RSC Adv., 2014, 4, 56445-56454. [4] S. Park, J. An, J.R. Potts, A.Velamakanni, S.Murali, R.S. Ruoff, Carbon, 2011, 49, 3019-3023. [5] L. Guardia, S. Villar-Rodil, J.I. Paredes, R. Rozada, A. Martínez-Alonso, J.M.D. Tascón, Carbon, 2012, 50, 1014-1024.

125

Wuhan, China

Poster Presentation PP57

De-NOx Activity of TiO2/Graphene Photocatalysts: “In-situ” vs “Exsitu” Synthesized TiO2 N. Todorova, A. Trapalis, T. Giannakopoulou, I. Papailias and C. Trapalis* Institute of Nanoscience and Nanotechnology, NCSR “Demokritos”, Agia Paraskevi, Attikis, 15341, Greece. e-mail: [email protected]

Abstract: Graphene-modified TiO2 is regarded as highly promising photocatalyst because of favourable e- transfer from TiO2 to the graphene layers. Reduced graphene oxide (rGO) is mainly used for modification of TiO2 owing to its hydrophilic properties and semiconductor behaviour [1]. It has been established that the activity of the TiO2/rGO photocatalysts is dependent on the efficient contact between the two components [2]. Homogeneous distribution and improved interface contact between TiO2 and rGO is pursued. In the present work, the influence of the coupling method of TiO 2 with graphene sheets on the photocatalytic behaviour of TiO2/rGO composites in removal of NOx pollutants from air was investigated. Two different routes were employed for the preparation of TiO 2/rGO composites: (a) TiO2 synthesized by sol-gel method (ex-situ) was mixed with exfoliated Graphite oxide (GtO) and hydrothermally treated at 180 oC; (b) TiO2 was synthesized in presence of graphene oxide (in-situ) at hydrothermal conditions. In both cases, the GtO used was initially prepared via modified Hummers method. The loading concentrations of the GtO were 0.01 wt%, 0.1 wt% and 1 wt%, which undergo partial reduction during the thermal treatment. The crystalline and electronic structure, morphology, porosity and light absorption of the manufactured composites were comparatively investigated. X-ray diffraction peaks originating from the GtO were not recorded indicating formation of well mixed TiO2/graphene nanocomposites. The Raman spectra revealed presence of rGO in the composites with the highest (1wt%) loading. The morphology of the composites with in-situ synthesized TiO2 exhibited more layered orientation and higher BET specific surface area in comparison to the composites with ex-situ prepared TiO2. All rGO-containing photocatalysts showed small but gradual decrease of Eg from 3.2 eV to 3.08 eV with the increase of GtO loading. The photocatalytic activity of the two groups of composites was evaluated in NOx removal from ambient air under visible light irradiation following standard procedure. Both types of TiO 2/rGO materials exhibited enhanced activity in comparison to the pure TiO 2. The composites with 0.1 wt% and 0.01 wt% GO showed significant increase in NOx removal. The composites with in-situ synthesized TiO2 demonstrated superior De-NOx ability with significant decrease of the NO2 evolution in the air. It was related to better interfacial contact between the TiO2 and rGO layers leading to more efficient e - - h+ charge separation and reduced recombination. In addition, the more efficient one-step preparation route, which does not include costly TiO2 calcination process, renders these materials attractive for manufacture of TiO2/rGO composites and application as photocatalysts for air purification.

Keywords: Graphene • TiO2 • Photocatalysis • NOx removal • Composites [1] C. Chen, W. Cai, M. Long, B. Zhou, Y. Wu, D. Wu, Y. Feng, ACS Nano, 4 (2010) 6425. [2] Y. Zhang, N. Zhang, Z.R. Tang, Y.J. Xu, Phys. Chem. Chem. Phys., 14 (2012) 9167.

126

Wuhan, China

Poster Presentation PP58

Synthesis of g-C3N4/BiPO4 with core-shell structure by one-step hydrothermal method for efficient decomposition of dimethyl phthalate in aqueous solution Yan Wang, Ying Yu* College of Physical Science and Technology, Central China Normal University, Wuhan 430079, China email: [email protected]

Abstract: Graphitic carbon nitride (g-C3N4), as two dimensional nanosheet materials, has attracted tremendous attention owing to its unique structure of two-dimensional frameworks composed of tris-triazine connected via tertiary amines.[1][2] Moreover, G-C3N4 based semiconductor composites show remarkably photocatalytic performance.[3] Herein, g-C3N4/BiPO4 composites with core-shell structure were prepared by a novel one-step hydrothermal method and their morphology and composition are shown in Figure 1. Compared with bare BiPO 4 and P25, the g-C3N4/BiPO4 composites exhibited much higher photocatalytic activity for methylene blue (MB) and dimethyl phthalate degradation. The corresponding rate constant k values of 0.075CB (A series of gC3N4/BiPO4 composites with different mass of g-C3N4 nanosheets added during the preparatioin were marked as xCB. For example, 0.075CB means that the content of g-C3N4 was 0.075g) composites for MB degradation was 0.08662 min -1, which was 1.6 times higher than that of P25. The main active species of the as-prepared g-C3N4/BiPO4 were h+ and ·OH through radicals and holes trapping experiments. The photocurrent densities of 0.075CB composites measured by transient photocurrent responses was 2 times as much as that of BiPO4 and 87 times as much as that of g-C3N4 nanosheets. For semiconductor composites, the existence of g-C3N4 distinctly improves the separation efficiency of electron and holes. [4]

Figure 1 TEM images of as-prepared g-C3N4 nanosheets (a), 0.075CB composites (b) and (c), HRTEM image of 0.075CB composites (d), and EDX spectrum for the selected area in 0.075CB composites (e1) and (e2). Keywords: Graphitic carbon nitride; one-step hydrothermal; photocatalytic; dimethyl phthalate [1] S. Cao, J. Low, J. Yu and M. Jaroniec, Adv. Mater. 2015, 27(13):2150-76 [2] P. Niu, L. Zhang, G. Liu and H.M. Cheng, Adv. Funct. Mater. 2012, 22, 4763–4770 [3] C. Pan, J. Xu, Y. Wang, D. Li and Y. Zhu, Adv. Funct. Mater. 2012, 22, 1518–1524 [4] L. Yu, G. Li, X. Zhang, X. Ba, G. Shi, Y. Li, P.K. Wong, J.C. Yu and Y. Yu, ACS Catal. 2016, 6, 6444−6454

127

Wuhan, China

Poster Presentation PP59

MoS2 Nanosheet Decorated Porous SnO2 Nanofibers for Enhanced Catalytic Reduction of 4-nitrophenol** Zhenwei Zhang, Xiuqing Qiao*, Dongfang Hou, Dongsheng Li* College of Materials and Chemical Engineering, Hubei Provincial Collaborative Innovation Center for New Energy Microgrid, Key Laboratory of Inorganic Nonmetallic Crystalline and Energy Conversion Materials, China Three Gorges University, Yichang 443002, PR China e-mail: [email protected], [email protected]

Abstract: One dimensional (1D) MoS2 nanosheets decorated porous SnO2 nanofibers (MoS2/SnO2) hybrid nanostructures were fabricated via the electrospinning–hydrothermal two-step process. The MoS2 nanosheets with ultrathin structure were intensive and crossed arranging on the porous SnO 2 nanofibers. The catalytic activities of the MoS 2/SnO2 hybrid nanostructures for the reduction of 4nitrophenol (4-NP) with KaBH4 were evaluated. It was suggested that the MoS2/SnO2 hybrid nanostructures exhibited enhanced catalytic activity compared to the individual SnO2 nanofiber and the MoS2 nanosheets for the reduction of 4-NP, which was ascribed to the synergistic effect of defect-riched MoS2 nanosheets and porous SnO2 nanofibers. The MoS2/SnO2 hybrid presented here has the potential to replace noble metals for certain catalytic applications. 2.0

1min 2min 3min 4min 5min 6min 7min 8min 9min 10min 11min 12min 13min

Absorbance/a.u.

1.5

1.0

0.5

4-NP 0.0 250

300

350

400

450

500

/nm

Acknowledgement: This work was financially supported by the NSFC (Nos. 51572152,51502155,21373122,21673127 and 21671119) and the State Key Laboratory of Structural Chemistry, FJIRSM (20170020).

Keywords: Porous SnO2 nanofibers • MoS2 nonasheets • heterostructure • catalytic activity • [1] [2] [3] [4]

Yunpeng Huang, Yue-E Miao, Nanoscale, 2014, 6, 10673-10679 Peng Zhang, Changlu Shao, Nanoscale, 2011,3, 3357-3363 Tianran Lin, Jing Wang, J. Phys. Chem. C, 2015, 119 (24), 13658-13664 Zehong Cheng, Benzhao He, J. Mater. Chem. A, 2015,3, 1042-1048

128

Wuhan, China

Poster Presentation PP60

Visible-light enhanced photoelectrocatalytic ethanol oxidation based on two dimensional Pt-BiOI electrode Chunyang Zhai,* Jiayue Hu, Mingjuan Sun, Mingshan Zhu,* School of Materials Science and Chemical Engineering, Ningbo University, Ningbo 315211, China *Email: [email protected], [email protected]

Abstract: Since Kamat’s group[1] first reported the great improvement of methanol oxidation activity by using noble metal deposited on TiO2 surface under UV light irradiation, the traditional noble metal hybridized with the photo-responsive semiconductor as anode catalysts grabbed more and more attentions for improving the activity and stability of fuel cell reaction[2-4]. BiOI, with novelty tetragonal layered structure and narrower bandgap, displays outstanding photocatalytic activity under visible light irradiation. Herein, two dimensional (2D) BiOI nanosheets was obtained by a simple hydrothermal method and then worked as support for deposited Pt nanoparticles. Compared with traditional electrocatalytic oxidation, the as-prepared Pt/BiOI nanosheets modified electrode displayed a significant enhancement in the catalytic activities and stabilities for ethanol oxidation under visible light irradiation. The forward current density of Pt-BiOI electrode can be reached to 1593 mA mg-1Pt under visible light irradiation, which is 3.8 times higher than the electrode under dark condition (421 mA mg-1Pt). The synergistic effects of electro– and photo– catalytic together with efficient interfacial electron transfer of the Pt/BiOI contribute to this enhanced catalytic performance. This result shows that the 2D BiOI nanosheets can be used as promising photoactived support in the fields of solar and chemical energy conversion and also provides more insights into developing novel visible light photoactived electrode in direct ethanol fule cell.

Fig. 1. (A): SEM image of BiOI samples; (B): TEM image of Pt/BiOI samples; (C): The CV curves of PtBiOI electrode without (a) and with (b) visible-light irradiation in 1.0 M CH3CH2OH + 1.0 M KOH solution at 50 mV s-1 scan. Keywords: Photoelectrocatalysts; BiOI; Visible light; Ethanol oxidation; Two dimensional [1] K. Drew, G. Girishkumar, K. Vinodgopal, P.V. Kamat, J. Phys. Chem. B, 2005, 109, 11851-11857. [2] C.Y. Zhai, M.S. Zhu, F.Z. Pang, D. Bin, C. Lu, M.C. Goh, P. Yang, Y.K. Du, ACS Applied Materials & Interfaces，2016, 8, 5972-5980. [3] C.Y. Zhai, M.S. Zhu, D. Bin, H.W. Wang, Y.K. Du, C.Y. Wang, P.Yang, ACS Applied Materials & Interfaces, 2014, 6 (20), 17753-17761. [4] C.Y. Zhai, J.Y. Hu, M.J. Sun, M.S. Energy Technology, 2016, DOI: 10.1002/ente.201600637.

129

Wuhan, China

Poster Presentation PP61

High photocatalytic performance of Ag/TiO2 nanofibers: photodegradation of organic dye and photocatalytic H 2 generation Ting-Han Lin, Po-Yeh Wu, Yin-Hsuan Chang, and Ming-Chung Wu* Department of Chemical and Materials Engineering, College of Engineering, Chang Gung University, Taoyuan 33302, Taiwan *e-mail: [email protected]

Abstract: Titanium dioxide is the one of promising material in research field of photocatalyst and thus attracted widespread research interests. [1-2] There have been a plenty of efforts in narrowing the intrinsic bandgap as well as reducing recombination behaviour of electron-hole pairs.[3-4] Metal doping and non-metal doping into TiO2 are considered as solutions to modify the wide bandgap. [5-8] Especially the specific metal-ion in TiO2 lattice may effectively separate electrons-hole pairs and lower the recombination rate. On the other hand, one-dimensional TiO2 such as nanofiber, nanotube, and nanowire can be much easier to produce an elongated electrical network than nanoparticles and reach a high crystallinity after calcination. In this study, we prepared a series of transition metal doped TiO2 nanofibers (metal/TiO2 NFs) through hydrothermal synthesis and followed by thermal treatment. There are eleven types of transition metal, including Ag, Au, Co, Cr, Cu, Fe, Ni, Pd, Pt, Y and Zn, which have been doped into TiO2. For the preparation of metal/TiO2 NFs, we suspended TiO2 anatase powder and 1 mol% transition metal precursor in 10.0 M NaOH solution, followed by a treatment in a teflon-lined autoclave under 150 oC for 24 h. In order to exchange sodium ions for protons, the various metal doped sodium titanate were washed by 0.10 M HCl. Then, the obtained nanofibers was washed in deionized water to be neutralized and filtered. The product was further dried in the air at 80 oC. Finally, all of these powder was kept calcined separately under 500, 550, 600, 650, and 700 °C for 12 h, and the heating rate is 5 °C/min. The photocatalytic activity of each metal/TiO2 NFs had been determined by photodegradation of organic dye and photocatalytic hydrogen production. Hence, we developed a systematically experiments to find out the proper calcination condition and metal-doping concentration. Among these metal/TiO2 NFs, Ag/TiO2 NFs possessed highest photocatalytic activity than others. For the test of photodegradation of methyl orange under UV irradiation, 0.5 mol%-Ag/TiO2 exhibits the fastest decoloration phenomenon. Moreover, Ag/TiO2 NFs show the capability in the photocatalytic hydrogen production. The hydrogen production rate is 500 μmol/g·hr under UV-B irradiation. Keywords: TiO2 •metal doped TiO2 •photodegradation •photocatalytic hydrogen production [1] [2] [3] [4] [5] [6] [7] [8]

A. Fujishima, K. Honda, Nature 1972, 238, 37. A. Kudo and Y. Misekia, Chem. Soc. Rev., 2009, 38, 253-278 M. Pelaez, N.T. Nolan, S.C. Pillai, M.K. Seery, P. Falaras, A.G. Kontos, P.S.M. Dunlop, J.W.J. Hamilton, J.A. Byrne, K. O'Shea, M.H. Entezari and D.D. Dionysiou, Appl. Catal. B- Environ., 2017, 125, 331-349 M.-C. Wu, C.-H. Chen, W.-K. Huang, K.-C. Hsiao, T.-H. Lin, S.-H. Chan, P.-Y. Wu, C.-F. Lu, Y.-H. Chang, T.-F. Lin, K.-H. Hsu, J.-F. Hsu, K.-M. Lee, J.-J. Shyue, K. Kordás and W.-F. Su, Sci. Rep., 2017, 7, 40896 J. Maragatha, S. Rajendran, T. Endo and S. Karuppuchamy, J. Mater. Sci. Mater. Electron, 2016, doi:10.1007/s10854-0166185-7 B. Liu, H.M. Chen, C. Liu, S.C. Andrews, C. Hahn and P. Yang, J. Am. Chem. Soc., 2013, 135, 9995−9998 S. Sood, A. Umar, S. K. Mehta, S. K. Kansal, J. Colloid Interface Sci., 2015, 450, 213-223 Y. Hu, X. Song, S. Jiang, C. Wei, Chem. Eng. J., 2015, 274, 102-112

130

Wuhan, China

Poster Presentation PP62

Copper doping effects on photocatalytic properties of TiO 2 NFs Kuo-Ping Chiang, Po-Yeh Wu, Yin-Hsuan Chang, Ting-Han Lin and Ming-Chung Wu* Department of Chemical and Materials Engineering, College of Engineering, Chang Gung University, Taoyuan 33302, Taiwan *e-mail: [email protected]

Abstract: Photocatalytic processes can be used to address several aspects of modern renewable energy production, such as efficient solar cell electrodes, photocatalytic hydrogen production and photocatalytic water splitting. Titanium dioxide play an import role in this field and have become an indispensable candidate for application due to its feature such as chemical and thermal stability, strong oxidizing power, highly active photocatalytic activity, and photostability. [1-4] Thus, the doping of metal ions into TiO2 has been studied to enhance the photocatalytic activity. [5-9] In this study, copper nitrate was adopted as dopant to synthesize Cu/TiO2 NFs with hydrothermal method following by the thermal annealing treatment. Then, we systematically developed a series of copper ion doped titanium dioxide nanofibers (Cu/TiO2 NFs) at different calcination temperatures for 12 h. The corresponding crystal structure with various doping concentration were also investigated. The reflectance behavior of Cu-doped TiO2 NFs is enhanced by increasing the doping concentration at the calcination temperature of 600oC. For the test of photocatalytic hydrogen production and photodegradation of methyl orange under UV irradiation, 0.5 mol%-Cu/TiO2 exhibits highly active performance.The developed 0.5 mol% Cu-doped TiO2 NFs may be potential alternative of the commercial AEROXIDE® P25 for photocatalytic applications in the decomposition of organic dyes and hydrogen generation under UV irradiation. This study can be useful for further study in the crystal structure engineering and the development of photocatalytic applications. Keywords: Cu-doped TiO2 NFs •photodegradation •photocatalytic hydrogen production [1] R. Asahi, T. Morikawa, T. Ohwaki, K. Aoki and Y. Taga, Science, 2001, 293, 269. [2] T. Ohno, M. Akiyoshi, T. Umebayashi, K. Asai, T. Mitsui and M. Matsumura, Appl. Catal., A, 2004, 265, 115-121. [3] J. Yu, J. Xiong, B. Cheng and S. Liu, Appl. Catal., B, 2005, 60, 211-221. [4] K. Awazu, M. Fujimaki, C. Rockstuhl, J. Tominaga, H. Murakami, Y. Ohki, N. Yoshida and T. Watanabe, J. Am. Chem. Soc., 2008, 130, 1676-1680. [5] V. Subramanian, E. Wolf and P. V. Kamat, J. Phys. Chem. B, 2001, 105, 11439-11446. [6] H. Irie, Y. Watanabe and K. Hashimoto, J. Phys. Chem. B, 2003, 107, 5483-5486. [7] S. Rengaraj and X. Z. Li, J. Mol. Catal. A: Chem., 2006, 243, 60-67. [8] D. B. Hamal and K. J. Klabunde, J. Colloid Interface Sci., 2007, 311, 514-522. [9] K. Kočí, K. Matějů, L. Obalová, S. Krejčíková, Z. Lacný, D. Plachá, L. Čapek, A. Hospodková and O. Šolcová, Appl. Catal., B, 2010, 96, 239-244.

131

Wuhan, China

Poster Presentation PP63

In situ growth of WO3 nanoplates on g-C3N4 with enhanced photocatalytic performance ** Bo Chai*, Mengqiu Xu, Juntao Yan and Chunlei Wang School of Chemical and Environmental Engineering, Wuhan Polytechnic University, Wuhan 430023, P. R. China

Abstract: As a promising technology, photocatalysis has been widely studied in various fields such as environmental purification, solar energy conversion, and water splitting for H 2 evolution, etc. Graphite carbon nitride (g-C3N4), a polymeric organic semiconductor with visible light response, possesses appropriate band position and band gap, high chemical and thermal stability, feasible and economical bulk fabrication, which make it become a promising photocatalyst in the photocatalytic field. Nevertheless, the photocatalytic efficiency of bare g-C3N4 is limited owing to the high recombination rate of photogenerated electron-hole pairs. To enhance the photocatalytic activity, construction of composites has been extensively explored. In this paper, the WO 3/g-C3N4 composites were synthesized by in situ growing WO3 nanoplates on the surface of g-C3N4. The obtained composites showed improved visible light photocatalytic activity towards Rhodamine B (RhB) aqueous solution than that of pure WO3 and g-C3N4. The samples were characterized by thermogravimetric analysis (TG) to determine the weight ratios of WO3 in the WO3/g-C3N4 composites, as shown in Fig. 1a. According to the results, the mass contents of WO3 in the composites were estimated to be 11.6wt%, 18.6wt%, 33.4wt% and 49.3wt%, respectively. Fig. 1b showed the XRD patterns of WO 3/g-C3N4 composites with different WO3 amounts. As can be seen that there is a broad peaks at about 27.6°, which is characteristic peak of g-C3N4 corresponding to the (002) plane. The peaks attributed to the WO3 could be observed in all the WO3/g-C3N4 composites. Furthermore, the intensities of g-C3N4 become weaker with increase the contents of WO3 in the composites. The photocatalytic activities of as-prepared composites were investigated comparatively. The results indicated that the composites with 18.6 wt% WO3 content exhibited highest photocatalytic activity. The enhanced photocatalytic performance is mainly attributed to the suitable energy band positions between WO3 and g-C3N4, which favors the effective separation of electron-hole pairs.

Fig. 1 TG curves (a) and XRD patterns (b) of WO3/g-C3N4 composites with different WO3 contents.

Keywords: WO3/g-C3N4 composite • photocatalytic • visible light • degradation [1] [2] [3]

L.F. Cui, X. Ding, Y.G. Wang, H.C. Shi, L.H. Buang, Y.H. Zuo, S.F. Kang, Appl. Surf. Sci.., 2017, 391, 202-210. S.F. Chen, Y.F. Hu, S.G. Meng, X.L. Fu, Appl. Catal. B: Environ., 2014, 150, 564-573. J.L. Zhao, Z.Y. Ji, X.P. Shen, H. Zhou, L.B. Ma, Ceram. Int., 2015, 41, 5600-5606.

132

Wuhan, China

Poster Presentation PP64

Immobilization and Photocatalytic Activity Research of Highly Dispersed Magnetic Fe3O4 on TiO2 Qiuhong Liu, Qiong Sun* College of Materials Science and Engineering, Qingdao University of Science and Technology, Qingdao, China State Key Laboratory of Photocatalysis on Energy and Environment, Fuzhou University, Fuzhou, China e-mail: [email protected]

Abstract: TiO2 is one of the most promising oxides in photocatalysis. However, the low quantum efficiency caused by the relatively high and rapid recombination rate of photogenerated electron-hole pairs has deeply limited its photocatalytic activity and application[1]. It is reported that the metal ions can reduce the recombination center for they can act as the mediator of the interfacial charge transfer, so as to suppress the electron-hole pair recombination[2]. Among numerous elements, iron is a popular candidate because Fe3+ can form a shallow charge trap to reduce the electron-hole recombination[3]. As one of the ferric oxides, magnetite (Fe3O4) owns two types of Fe ions, Fe2+ and Fe3+, which can be transformed into each other in in-situ during the Fenton reaction. As a result, the TiO2 photocatalyst combined with Fe3O4 is inferred to result in a higher catalytic activity than that containing only Fe2+ or Fe3+ ions. In this study, the immobilization of magnetic Fe3O4 onto nanoporous TiO2 (TiO2-Fe) was carried out from a developed atmosphere calcination method, and Fe2(C2O4)3 was employed as the iron source. Taking the reactive brilliant red dye X3B as the substrate, the photocatalytical degradation reaction by TiO2-Fe was proceeded under the xenon lamp irradiation to evaluate its photoactivity. The photodegradation by blank TiO2 with equal amount Fe3+ was also carried out for the comparison of the activity between the free Fe3+ and immobilized iron. The result shows that: (1) The magnetite Fe3O4 was successfully loaded onto the surface of nanoporous TiO2 by a calcining method. (2) In the photocatalytic experiment, the 200:1(mass ratio of TiO2:Fe) TiO2-Fe sample exhibited excellent photocatalytic activity, which was much higher than that of blank TiO2 and even with free Fe3+ (Fig. 1a). (3) When H2O2 was added, the photo-Fenton reaction was induced to further accelerate the degradation of X3B (Fig. 1a). Moreover, the Inductive Coupled Plasma Emission Spectrometer (ICP) characterization of the recycled TiO2-Fe and the cycling experiment (Fig. 1b) both showed that immobilization of iron onto TiO2 was extremely stable, which indicated the great potential of this new composited photocatalyst for a practical application. 1.0

1.2 No photocatalyst 3+ TiO2+Fe TiO2 TiO2-Fe(200:1) TiO2-Fe(200:1)+H2O2

1.0 0.8

1 2 3 4 5

0.8

C/C0

C/C0

0.6

0.6

0.4

0.4 0.2

0.2 0.0 0

a 10

0.0

20

30

40

50

60

0

b

100

Time/min

200

300

Time/min

400

500

3+

Fig. 1 (a) Photocatalytic activities of TiO2, TiO2-Fe (200:1), TiO2 with free Fe and TiO2-Fe (200:1) with H2O2 for the X3B degradation under irradiation, (b) The photocatalytic cycle degradation curves of TiO2-Fe (200:1). Keywords: immobilized • TiO2-Fe • photocatalyst • photo-Fenton reaction • cycling experiment [1] [2] [3]

A. Kudo, Y. Miseki, Chem. Soc. Rev., 2009, 38, 253-278. J. Zhang, C. Pan, P. Fang, et al., ACS Appl. Mater. Interfaces, 2010, 2, 1173-1176. X. Yang, C. Cao, L. Erickson, et al., Appl. Catal., B, 2009, 91, 657-662.

133

Wuhan, China

Poster Presentation PP65

Photo-reactivity and mechanism of g-C3N4 and Ag co-modified Bi2WO6 microsphere under visible light irradiation ** Xiaoping Xiao, Ting Zhang, Jianhong Wei* Address: Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan 430072, PR China

Abstract: Recently, a novel metal-free polymeric semiconductor, graphitic carbon nitride (g-C3N4), had attracted much attention for its high chemical and thermal stability, a medium bandgap of ~2.7 eV, which makes it an ideal visible-light-induced photocatalysts[1-2]. Nevertheless, pure g-C3N4 suffers from a high recombination rate of photogenerated charge carriers, low specific surface area, and correspondingly resulting in low visible-light-driven photocatalytic performance.3 Given the above analysis, designing an artificial multi-component photocatalytic system composed of Bi2WO6, g-C3N4 and Ag with flower-like superstructures maybe is an ideal way for expanding the light absorption region, improving the quantum yield and the photocatalytic activity. In this work, C3N4@Ag-Bi2 WO6 with flower-like architecture was successfully prepared through a facile process. The C3N4@Ag-Bi2WO6 particles with diameters about 2- 4 μm exhibit remarkable enhanced visiblelight absorption and charge separation efficiency. Compared with the Bi2 WO6, Ag-Bi2 WO6 and C3N4@Bi2WO6 systems, the C3N4@Ag-Bi2 WO6 system exhibits optimal photocatalytic activity in both the degradation of RhB and producing hydrogen out of water under visible light irradiation. This result may be attributed to the synergy effect of Ag, g-C3N4 and Bi2WO6 nanophase-structures in the C3N4@Ag-Bi2 WO6 composites, which results in a fast charge separation and slow charge recombination by a Z-scheme mechanism and ultimately resulting in a higher photocatalytic activity.

Keywords: C3N4-based nanocomposite; silver; Bi2WO6; Z-scheme mechanism; photocatalysis. [1] Wang, X. C., Maeda, K.; Thomas, A.; Takanabe, K.; Xin, G.; Carlson, J. M.; Domen, K.; Antonietti, M. Nat. Mater. 2009, 8, 76-80. [2] Liu, J.; Liu, Y.; Liu, N.Y.; Han, Y. Z.; Zhang, X.; Huang, H.; Lifshitz, Y.; Lee, S. T.; Zhong, J.; Kang, Z. H. Science 2015, 347, 970-974. [3] Huang, Z. F.; Song, J. J.; Pan, L.; Wang, Z. M.; Zhang, X. Q.; Zou, J. J.; Mi, W. B.; Zhang, X. W.; Wang, L. Nano Energy 2015, 12, 646-656.

134

Wuhan, China

Poster Presentation PP66

Influence of the anti-solvents on the performance of the methylammonium lead triiodide perovskite solar cells Bo-Yi Liou and Kun-Mu Lee* Department of Chemical and Materials Engineering, College of Engineering, Chang Gung University, Taoyuan 33302, Taiwan *e-mail: [email protected]

Abstract: Since the adopt of methylammonium lead triiodide (CH3NH3PbI3; MAPbI3) perovskite as light harvester in the solar cells with power conversion efficiency (PCE) of 3.8% in 2009 [1]. The PEC has boosted to the current world record of 21.0% in 2016. The rapid advances in perovskite solar cells are attributed to its excellent optoelectronic properties such as remarkably high absorption coefficient [2], low exciton binding energy about 0.03 eV[3], carrier diffusion length in the range of micrometer owing to the recombination occurring on a timescale of hundreds of nanoseconds[4], and tunable energy bandgap[5]. However, the surface coverage and the morphology of MAPbI3 are hardly to control, because the nucleation rate and crystal growth rate is inconsistent. To overcome this issue, the antisolvents usually were introduced during the preparation of MAPbI3 thin film. There is many kind of anti-solvents, it should be not dissolving the perovskite materials and is miscible with DMSO and γ-butyrolactone (GBL). Therefore, selecting antisolvent becomes an important factor to fabricate high performance perovskite solar cells. Here, we have a systematic studied different types of anti-solvent including toluene (TL), chloroform (CF), chlorobenzene (CB), dichlorobenzene (DCB), isopropyl alcohol (IPA), and some common organic solvents. We find that low dielectric constant (