Fenton-like nanocatalyst for photodegradation of

Carbohydrate Polymers 197 (2018) 17–28

Contents lists available at ScienceDirect

Carbohydrate Polymers journal homepage: www.elsevier.com/locate/carbpol

Fenton-like nanocatalyst for photodegradation of methylene blue under visible light activated by hybrid green DNSA@Chitosan@MnFe2O4

T

⁎

Kamel Shoueira, , Hamdy El-Sheshtawyb, Mohammed Misbaha, Hamza El-Hosainya, Ibrahim El-Mehassebb, Maged El-Kemarya,b a b

Institute of Nanoscience & Nanotechnology, Kafrelsheikh University, 33516 Kafrelsheikh, Egypt Faculty of Science, Kafrelsheikh University, 33516 Kafrelsheikh, Egypt

A R T I C LE I N FO

A B S T R A C T

Keywords: MnFe2O4 Chitosan Photo-Fenton Adsorption Photodegradation

High efficient 3,5-Dinitrosalicylic acid/Chitosan/MnFe2O4 (DNSA@CS@MnFe2O4) nano photocatalyst was prepared to enrich both adsorption and photodecomposition under visible light. This paper focused on the importance of DNSA@CS as an excellent connector between methylene blue (MB) and MnFe2O4 for accelerating photodegradation with the encouragement of photo-Fenton catalytic reagent hydrogen peroxide (H2O2). The optimum conditions were: contact time, 30 min, H2O2 concentration, 0.16 M, pH factor 9 and dosage 0.06 g/l at R.T, allowing excellent catalytic achievements 98.9% degree of decolorization in 30 min. More interestingly, the hybrid DNSA@CS@MnFe2O4 mechanism explained on the basis of coexistence of Mn2+/Mn3+ and Fe3+/Fe2+ redox couples during the reaction. The photocatalytic decolorization experimentally affirmed the suitability of DNSA@CS@MnFe2O4 obeying Langmuir-Hinshelwood model. Also, the nano-catalytic system was stable even after five runs. The prepared nanostructured catalyst provides simple fabrication to promote deep understand criteria for the mechanistic role of MnFe2O4 catalyst for degradation of MB molecules.

1. Introduction Water polluted with dyes is a catastrophic effect on the surrounded environment. At this moment, the textile finishing and dyeing industries contribute more than 20% of the total water pollution (Konstantinou & Albanis, 2004). These dyes as example derived from petroleum intermediate and coal tar products with annually production 7 × 105 metric tons in the industry and about 280L of natural water is being consumed for dying every kg of cloth (Alharbi & El-Sheshtawy, 2017; Bensalah, Alfaro, & Martínez-Huitle, 2009; Shoueir, Sarhan, Atta, & Akl, 2016) High COD, high intensity of color, stability to oxidizing agents and inhibition of photosynthesis reactivity is apart from the hazard effect of organic dyes. Moreover, many dyes are prepared from carcinogens such as aromatic compounds and benzidine (Baughman & Perenich, 1988; Kant, 2012; Prado, Bolzon, Pedroso, Moura, & Costa, 2008). Currently, treatment of such obvious and challenging effluents by different technologies is necessary to minimize their potential impacts on the environment, including physical, chemical, and even biological adsorption processes are not sufficient (Alnuaimi, Rauf, & Ashraf, 2007; Bensalah et al., 2009; Houas, Bakir, Ksibi, & Elaloui, 1999; Lin & Peng, 1996; Shoueir et al., 2016; Singh & Arora, 2011). Nowadays, advance

⁎

Corresponding author. E-mail address: [email protected] (K. Shoueir).

https://doi.org/10.1016/j.carbpol.2018.05.076 Received 8 March 2018; Received in revised form 27 April 2018; Accepted 25 May 2018 Available online 26 May 2018 0144-8617/ © 2018 Published by Elsevier Ltd.

oxidation processes (AOPs) are becoming more and more important technologies for water treatment, especially for hardly biodegradable contaminants (Jiao et al., 2018). Among the AOPs, the classical Fentonlike catalyst is widely used, due to the two main catalysts H2O2 and Fe2+/Fe3+ enhance the organic degradation potency. Nevertheless, Fenton homogeneous catalysis has some drawbacks. For example, efficient Fenton-system at low pH (2–3.7), so strong acids required to adjust the pH of the wanted wastewater containing high levels of iron to reach (Chen et al., 2011). Therefore, these disadvantages limit its widespread application. As common, the heterogeneous approach is green and highly efficient. Several and different catalysts such as palladium nanocatalyst blended with natural bio-polymers as chitosan and cellulose composite was fabricated by different routes (Baran, Baran, & Menteş, 2018; Baran & Menteş, 2016; Baran, Sargin, Kaya, & Menteş, 2016). In general, heterogeneous photocatalysis implying great potential such as simplest, dirt-cheap, green and free renewable treatment process. Consequently, oxidize mineralization of the water contaminants matrix into popular CO2, H2O and mineral acids by initiation of the highly oxidizing hydroxyl radicals (%OH) groups (Herrera, Kiwi, Lopez, & Nadtochenko, 1999). Within the exploration of efficient visible-light-driven photocatalysts, convenient magnetic cubic spinel nano ferrites MnFe2O4 is


K. Shoueir et al.

2.2. Synthesis of 3,5-dinitro salicylic acid-modified chitosan (DNSA@CS)

the most proper one. Good biocompatibility, high adsorption rate, and excellent optical property rather than CuFe2O4, NiFe2O4 and CoFe2O4 nanomaterials as reported (Goyal, Bansal, & Singhal, 2014; Yao et al., 2014). MnFe2O4 based hybrids are a vital solution towards the visible light, good responsive nano photocatalyst for detoxification of textile dyes with a narrow band gap of (2.0 ± 0.5 eV) (Li, Hou, Zhao, & Wang, 2011). Moreover, the coated MnFe2O4 nanomaterials were used to decompose Red X-3B, MB, Congo red under microwave-assisted synthesis from different dye systems. The particular aggregation of the MnFe2O4 declines their catalytic rate (Fang, Xiao, Yang, He, & Sun, 2015; Yang et al., 2014). As a result, it is important to develop heterogeneous Fenton system involving bimetal oxide catalyst to avoid precipitation of Fe3+ ions and to expand the acceptable pH range and controlling the size particles for enhanced catalytic efficiency. Chitosan (CS), is a pioneer amongst polysaccharides, composed of N-acetyl glucosamine, has fully advantages, like nontoxic, high chemical stability, biodegradable and the presence of bearing amino and hydroxyl groups as active sites (Gmurek, Foszpańczyk, OlakKucharczyk, Gryglik, & Ledakowicz, 2017). However, individual CS cannot be widely applied due to lack of mechanical, heat stability and solubility under acidic condition (pH 4 ± 0.5). So, enhancing functionality required an appropriate chemical modification to enhance and enforce functionality. To our knowledge, there is no previous work on the modification of CS by 3,5-dinitrosalcylic acid (DNSA). Therefore, the combination of DNSA@CS hopeful in size reduction to prolong its stability, achieve good stabilization of the photocatalyst with the assistant of H2O2 and prevent its agglomeration through squadron the photocatalyst in the polymer matrix to obtain bifunctional material, i.e., adsorbent and photocatalyst (Cui, An, Liu, Hu, & Liang, 2014). This returned to the ability of DNSA to provide best chemical synthons for construction of chemical bonded structural motifs (Cui et al., 2014). Zhaoyang Liu et al. synthesized chitosan/TiO2/Fe3O4; microspheres and possess highly adsorptive, self-regenerative and reusable properties (Liu, Bai, & Sun, 2011). Ling Xiao et al. Fabricated Cu2O/chitosanFe3O4 had efficient photo-decolorization of brilliant red X–3B under visible-light source (Farzana & Meenakshi, 2015). Sankaran Meenakshi et al. reported ZnO impregnated chitosan beads for photocatalytic removal of Methylene blue (MB) and Rhodamine B dyes using visible light irradiations (Cao, Xiao, Chen, & Cao, 2015). However, un controlled size and magnetic features of MnFe2O4 make recovery and reusability of photocatalyst difficult during the course of water remediation (Priya et al., 2016). Herein, our group developed a novel approach to introducing powerful microwave synthesis of green DNSA@CS@MnFe2O4 hybrid nanocatalyst for photodegradation/adsorption activity against MB molecule under visible light source in the presence of H2O2. Different factors were studied to attain the optimal conditions and the influence of stability and reusability. Besides, DNSA@CS, MnFe2O4, and DNSA@CS@MnFe2O4 have carried out a comparative study on dye detoxification at similar experimental conditions. The magnified DNSA@CS@MnFe2O4 separated smoothly by an external magnet and reused many times.

A collective mixture including 7 ml CS solution and 1.23 g DNSA stirred for 25 min, followed by adding 10 ml of DMF and 8.11 ml formaldehyde. The reactants mixture allowed to heat at 90 °C for 20 min into a Teflon-lined STRT SYNTH microwave oven (WX-4000). The aggregated pure yellow powder was soaked with a mixture of hot water and ethanol to get rid of odor and unreacted chemicals and the fine powder of DNSA@CS dried under vacuum at 65 °C for 12 h. 2.3. Preparation of DNSA@CS@MnFe2O4 A stoichiometric material of hydrated MnSO4·H2O and FeCl3·6H2O were dissolved in 40 ml DDI to obtain a lucent solution, then 1 M NaOH in 10 ml solution was dropped into the mixture to obtain co-precipitates as a precursor. Subsequently, the formed dark brown suspension added to 0.20 g of as-prepared DNSA@CS, then transferred again to a microwave oven for 50 min at 110 °C until rarely black coarse powder obtained. After completion, the net product was filtered, rinsed with mixed pure water and alcohol mixture to remove any residues. The precipitate was dried at 60 °C overnight. Following the above-mentioned procedures, Individual MnFe2O4 was prepared to compare between with DNSA@CS and DNSA@CS@MnFe2O4. Simple schematic representation is shown in Scheme 1a. 3. Measurements

2. Experimental

To detect the nanostructure of the synthesized materials HR-TEM, JEOL from Japan was used and operating at 200 keV. SEM, Sirion from FEI was used to recognize the surface morphology. SEM equipped with the pendent EDX detector (S–3400 N II, Hitachi, Japan). The samples covered with carbon tier to remove their further undesirable charging. DLS technique (Malvern Instruments Ltd, UK) used to measure the hydrodynamic sizes of the new DNSA@CS. To identify the chemical structures iS5-FTIR spectra (Model no. AUP1200343) spectrophotometer was used and adjusted in the range of 4000–500 cm−1 with a resolution of 1 cm−1. TGA analysis (SDT Q600 V20.5 Build 15) instrument at 20 kV, was used to study the thermal stability. The phase structure studied using XRD patterns, which recorded on Philips X Pert diffractometer in the 2θ range of 0–80° with a scan rate of 2° min−1. The specific surface area of the samples was determined by N2 sorption at 77 K using Brunauer–Emmett–Teller (BET) surface analyzer ((112370) Gemini, Micrometrics, USA) at 77.30 °C. Before operation running, the samples were degassed at 110 °C for 3 h under P/ Po = 0.99402 to remove any surface contaminants. Atomic force microscopy (AFM) WITec, Japan was used for surface roughness morphology. Vibrating Sample Magnetometer (VSM) (155 PAR) was used to measure the magnetic properties, the applied field dependence of magnetization takes the range of −20,000 Oe to 20,000 Oe at R.T. The remaining amount of manganese and iron in filtrate was detected by Inductive coupled plasma atomic emission spectrometry (ICP-AES) (Optima 5300DV, Perkin Elmer Type). UV–vis double beam spectrophotometer (Shimadzu UV-1208 model) was used to record absorbance of synthesized DNSA@CS, MnFe2O4 and hybrid DNSA@CS@MnFe2O4 and their photocatalytic efficiency.

2.1. Materials

4. Photocatalytic degradation and adsorption experiments

Chitosan (CS) powder low molecular wt. 50,000–190,000 Da and 3,5- dinitrosalicylic acid (DNSA), Manganese (II) sulfate monohydrate (MnSO4. H2O, 99%), and Iron (III) chloride hexahydrate (FeCl3·6H2O, 98%) were provided from Aldrich Chemicals, USA. Methylene blue (MB) (cationic dye, Mw = 319.85 g/mol) was prepared by dissolving definite weight in double distilled water (DDI). Other common reagents like glacial acetic acid, dimethylformamide (DMF), formaldehyde, sodium hydroxide, were used as an analytical chemical grade.

4.1. Light source The photocatalyst solution illuminated by Heber Visible (Annular Type) Photo reactor equipped with 500 W tungsten halogen lamp (1050 lm). The illumination light source carefully localized on the solution during treatment to prevent light dispersion. Moreover, the intensity of light measured regularly by lux meter, to ensure the best scattering of light onto the photocatalyst. An aliquot of the prepared 18


K. Shoueir et al.

Scheme 1. (a) Postulated synthesis of hybrid DNSA@CS@MnFe2O4 nanocatalyst, (b) Proposed activation mechanism of MB degradation onto DNSA@CS@MnFe2O4.

5. Results and discussion

samples at known irradiation time interval was taken out and analyzed at a λmax = 664 nm for cationic M.B dye.

5.1. Physicochemical evaluation of the nanoparticles 5.1.1. Photocatalyst morphological studies The morphology of the prepared nanoparticles was characterized by using TEM and SEM as shown in Fig. 1(a–f). The TEM image of MnFe2O4 clearly shows that the attached assembly particulates have some cubic uniform structure (yellow circles) having a mean diameter of 200 nm as presented in Fig. 1a. Furthermore, relative SEM analysis shows surface heterogeneity with large pits, pores, and scree like structure Fig. 1b. Fig. 1c, shows that the DNSA modified CS particles are smaller with a diameter of about 50 nm into a rope-like configuration, which agrees with particle size distribution analyzed from DLS. Similarly, the precursor DNSA@CS show extremely good monodisperse in the form of spherical structure shape as shown in Fig. 1d. Upon formation of DNSA@CS@MnFe2O4, the morphology is completely different as presented in Fig1e. As expected, MnFe2O4 dispersed, aggregated and stacked with DNSA@CS as a soft coral shape which affirms the closeness of MnFe2O4 over DNSA@CS (Fig. 1f). (Farzana & Meenakshi, 2013). In addition, the existence of many pleats on the surface of DNSA@CS@MnFe2O4, which viable for adsorption and discolor dye molecules and this may be due to successfully surface modification process. Moreover, the CS chains as a biopolymer are capable of bridge between two particles (Barbosa-Barros, García-Jimeno, & Estelrich, 2014; Fan et al., 2017). Fig. 1g shows the EDX spectra of the DNSA@CS@MnFe2O4 affirming existence of FeK and MnK in the elemental combination of hybrid which agree with the diagram obtained

4.2. Photodegradation experiments Typically, 40 mg of the synthesized preliminary photocatalyst added to 10 ml of basic M.B dye solution (10 mg l−1) irradiated under the effect of visible light at R.T. Then, adding 0.08 M of H2O2. 3 ml was taken off after intervals of time irradiation to extend the degree of decolorization (%). Removing of all the catalyst by external magnetic separation carefully after centrifugation is required. Before irradiation, the mixture stirring in the dark state in batch technique for at least 150 min to ensure adsorption saturation. After saturation, about 3 ml of the suspension collected, separated and the absorbance of the supernatant detected spectrophotometrically. In a batch degradation experiments, the extent of dyes removal in terms of percentage degradation calculated as follow:

C − Ct ⎞ Degradation rate (%) = ⎛ 0 × 100 ⎝ C0 ⎠ ⎜

⎟

(1)

Where, Co is the initial dye concentration (mg l−1) and Ct is the dye concentration (mg l−1) after time t (min).

19


K. Shoueir et al.

Fig. 1. (a) TEM of MnFe2O4; (b) SEM of MnFe2O4; (c) TEM of DNSA@CS and related D.L.S; (d) SEM of DNSA@CS; (e) TEM of DNSA@CS@MnF2O4; (f) SEM of hybrid DNSA@CS@MnFe2O4; and (g) EDX relative percentage of manganese and iron in the combination.

3090 cm−1 merged with the former band assigned to the stretching modes of −CH in the aromatic ring structure (Sebastian et al., 2015). The presence of a manifested band at 1559 cm−1, which attributed to stretching mode of eNO2 group in the position 3 and 5 in DNSA structure (Ahamed, Jeyakumar, & Burkanudeen, 2013), indicating the modification of CS by DNSA. The small intensity peak at 1644 cm−1 overlapping the amide band in CS structure, due to deformation vibration of eNH group proven a facile combination of DNSA and bare CS. Besides, the deformation of both the asymmetric eCH2 band at 1499 cm−1 and symmetric eCH2 at 1347 cm−1 becomes dominant, revealing the true enhancement of −CH bond (Riswan Ahamed, Azarudeen, Prabu, & Burkanudeen, 2015). The characteristic intense peak of MnFe2O4 located at 567 cm−1 due to the metal element –

from XRD patterns. The FT-IR spectrum of CS, DNSA@CS, DNSA@CS@MnFe2O4 hybrid and MnFe2O4 are shown in Fig. 2a. For bare chitosan (Fig. 2a), the absorbance of β-1-4 glycosidic linkage tunnel in the dominant peak at 1089 cm−1. The spectra at 1323 cm−1 assigned to carbon-nitrogen bond amino groups axial deformation (Baran, Menteş, & Arslan, 2015). Bands at 2928, 1640 and 1590 cm−1 belongs to the eCH backbone stretching vibration mode, amide I band (carbonyl ν (C]O)) and amide II (amine ν (NH2) tensions) (Azarudeen, Riswan Ahamed, Thirumarimurugan, Prabu, & Jeyakumar, 2016; M Hamed Misbah, Espanol, Quintanilla, Ginebra, & Rodríguez-Cabello, 2016; Mohamed Hamed Misbah et al., 2017). While, in case of DNSA@CS (Fig. 2b), an explicit characteristic peak appeared such as a feeble peak at 20


K. Shoueir et al.

Fig. 2. (a) FT-IR spectra of CS, DNSA@CS, DNSA@CS@MnFe2O4, and MnFe2O4 from up to down; (b) TGA profiles in argon atmosphere; (c) XRD patterns of bare CS, DNSA@CS, MnFe2O4 and DNSA@CS, MnFe2O4; and (d) Magnetic hysteresis (M-H) loops for the same materials.

DNSA@CS and MnFe2O4, which restricts the thermal motion of DNSA@CS chain in the composite. XRD patterns of pure CS, DNSA@CS, MnFe2O4, and DNSA@CS@ MnF2O4 hybrid are shown in Fig. 2c. The data shows that the addition of DNSA to CS does not change the spinal structure of the CS and the characteristic diffraction peaks appeared at 2θ = 9.8°,19.7°, 37.47°, 44.0°, 64.34°, and 77.54° remains constant. On the other hand, the addition of DNSA to CS broadened the crystalline peaks of CS at 19.7° due to insertion of DNSA, consequently, the peak intensity reduced and this returned to the steric hindrance effect (Abdelwahab & Helaly, 2017). Similarly, MnFe2O4 has well-crystallized peaks at 2θ = 29.66°, 34.88°. 42.70°, 56.44°, and 61.92°. However, we have found that adding DNSA@CS to the pure MnFe2O4 not change observed in the phase crystallinity of MnFe2O4, signifying that the dominance of the MnFe2O4 as a coating material and the synthesis did not destroy the features of organic DNSA@CS (Farzana & Meenakshi, 2015). Fig. 2d. Shows the magnetization hysteresis loops at 25 °C obtained by VSM technique and the obtained values of saturation magnetization (Ms), retentivity (Mr) and coercivity (Hci) are given in Table 1. Both MnFe2O4 and DNSA@CS@MnF2O4 nanoparticles exhibit a superparamagnetic behavior. The Ms value of magnified MnFe2O4 was reduced from 85.98 to 29.95 emu/g upon adding CS@DNSA, which ascribed to the basic diamagnetic features of organic materials such as CS

oxygen stretching vibration and still in the DNSA@CS with small shift and intense peak to be 559 cm−1 indicating the presence of strong electrostatic attraction force (Kafshgari, Ghorbani, & Azizi, 2017). The intrinsic vibration of octahedral and tetrahedral coordination M+2 and Fe+3 ions in the spinal responsible for that shift (Wang et al., 2015). Therefore, it can be concluded that the modification of CS by DNSA in the presence of MnFe2O4 successfully fabricated. TGA thermograms of the synthesized nanomaterials were assessed using TGA as in Figs. 2b and S1 TGA profile. In CS, the essential thermal degradation process at 213.99 °C due to both dehydration and depolymerization of the organic fragments in the saccharide and aromatic ring for DNSA@CS (Ma et al., 2017). In case of DNSA@CS, main decomposition temperature takes place before 200 °C (199.69 °C), lower than that of the degradation stage of original CS, revealing that DNSA@CS less thermally stable than CS. This decrease may be accounted for by the substitution of some free −NH2 groups with DNSA ring structure which destruction of backbone and lowering the crystallinity of CS (Baran & Menteş, 2016). For MnFe2O4 and DNSA@CS@MnFe2O4, it is clear that the weight loss over the temperature range from 50 °C to 850 °C not exceed ∼3.22% and 33.51% respectively, which may be believed to the formation of corresponding spinal phase (Shafiu, Topkaya, Baykal, & Toprak, 2013). Moreover, the thermal stability of DNSA@CS highly enhanced owing to the greater interaction between

Table 1 VSM measurements and surface characteristics of DNSA@CS; MnFe2O4; and hybrid DNSA@CS@ MnFe2O4 nanocatalyst Sample coded

DNSA@CS MnFe2O4 DNSA@CS@ MnFe2O4

Magnetic Properties

Surface Characteristics

Ms (emu/g)

Mr (emu/g)

Hci (g)

Total pore volume (cc/g)

Surface area (m2/g)

Pore volume (cc/g)

Pore radius Dv(r)

Average pore radius

1.045 85.98 29.95

0.006 2.92 8.59

98.36 122.28 484.02

3.18 2.35 4.95

153.04 69.42 219.36

0.33 0.74 2.43

18.45 A0 9.27 A0 11.450

2.4 nm 6.4 nm 1.56 nm

21


K. Shoueir et al.

and DNSA surrounding MnFe2O4, (Stoia, Muntean, Păcurariu, & Mihali, 2017). The neglected Ms and Mr for macromolecule DNSA@CS attributed to non-magnetic islands separating the magnetic domains, thereby decrease the values of Mc and Mr MnFe2O4 value (Almasian, Chizarifard, & Najafi, 2017; Topkaya, Kurtan, Baykal, & Toprak, 2013). Also, it can be seen the coercive force (Hci) which measure magnetocrystalline anisotropy getting more intense with MnFe2O4, due to the crystal size becomes smaller, which enlarge the area of the surface-tovolume ratio (Rivas et al., 2013). Similar results have been reported in the literature for the MnFe2O4 coated polyvinylpyrrolidone (Kazan et al., 2016; Shafiu et al., 2013). Table 1, shows the surface characteristics of materials. The data measured by BET observed that significant differences between the surface areas. In DNSA@CS@MnF2O4 hybrid formulation maximum porosity and surface area were detected due to wrapping MnFe2O4 into chemically modified CS scaffold. The BET increased from 153.04 to 219.36 m2/g due to electronic property, chemical stability can serve as an ideal coating matrix for growing nanoparticles and offer sufficient reactive sites. The increased pore volume determined from the desorption isotherm were 0.33, 0.74 and 2.43 cc/g for DNSA@CS, MnFe2O4, and DNSA@CS@MnF2O4, respectively. This returned to the closeness stack between MnFe2O4 and DNSA@CS particles (T. Liu, Zhang, Yan, Ye, & Chen, 2014). Fig. 3, shows the 3DAFM topography of the prepared materials. The average surface roughness calculated from the roughness profile of the 3DAFM images of DNSA@CS, MnFe2O4, and DNSA@CS@MnF2O4 are 52.29, 41.67, and 63.45 nm, respectively. These values are consistent with size measured from TEM images indicating that the DNSA@CS surface had become rough after coating with a hard layer from MnFe2O4. This behavior returned to clear deposition of a MnFe2O4 forming layer on the surface of DNSA@CS. Moreover, the increment in surface roughness is responsible for attaining adsorption saturation as stated in the literature (Kumar et al., 2014).

qe (mg / g ) =

(C0 − Ce ) Vl Mg

(2)

Where qe is the quantity of M.B adsorbed, C0 and Ce are initial and saturation concentration (mg/l), respectively, (V) is the volume of M.B solution and (M) is the mass of DNSA@CS, MnFe2O4, and DNSA@CS@ MnFe2O4 nanocatalyst. Pseudo-first-order and pseudo-second-order kinetic models are of the most important parameters to evaluate the interaction between the M.B molecule and nanocatalyst surfaces. Lagergren-first-order model, pseudo-second-order model, and intraparticle mass transfer diffusion model were applied to investigate the kinetics of adsorption. The empirical formula of these models represented as follow (El-Kemary et al., 2017).

log(qe − qt ) = logqe −

k1 2.303

(3)

t 1 t = + qt qt k2 qe2

(4)

qt =kp t 0.5 + C

(5)

Where qe and qt (mg/g) are the amounts of M.B adsorbed onto nanocatalyst at equilibrium and at time t, respectively; k1 is a constant rate of the pseudo-first-order (min−1) of the adsorption process and k2 is the pseudo-second-order rate constant (g mg−1 min−1) of adsorption. The k2 and correlation coefficient R2 was evaluated by plotting the t/qt versus t. As shown in Fig. S3 and Table 2, only DNSA@CS obeyed pseudosecond-order rate owing to higher R2 which closer to unity (0.91) and the qcal significantly agree with the qexp value. Therefore, the adsorption rate of DNSA@CS toward MB was probably controlled by the chemical adsorption process by sharing or electrons change between the two adsorbent/adsorbate surfaces (Fan et al., 2017; Kafshgari et al., 2017; Shoueir et al., 2016; A. Zhao, Tao, Xiao, & Su, 2017). In case of MnFe2O4 and DNSA@CS@MnFe2O4, the qe for MnFe2O4 was 46.1 mg/g is relatively close to the experimental qe 48.1 mg/g with a high R2 0.95 rather than second order and qe for the corresponding DNSA@CS@ MnFe2O4 was 112.6 mg/g while the experimental qe was 97.6 mg/g with R2 0.96, confirming that the adsorption of MB onto the magnified adsorbents only are better represented by Lagergren- pseudo- first-order kinetics. The rate constants of intraparticle diffusion, kid and C mainly determine the rate-determining step in the adsorption process. If the value of C is quite zero the adsorption process takes place by surface adsorption and the intraparticle diffusion. The value of C ultimately higher than zero so the intraparticle diffusion was not the rate-determining step for DNSA@CS during adsorption of MB and bulk mass transfer is the predominant one. On contrary, values of C for MnFe2O4 is 2.9 (mg g−1) and DNSA@CS@ MnFe2O4 is very low 0.6 (mg g−1) indicates that the adsorption process governed by intraparticle diffusion

5.2. Adsorption capacity evaluation Fig. S2 shows the UV–vis spectra of M.B dye suspension in contact with DNSA@CS, MnFe2O4, and DNSA@CS@MnF2O4 nanocatalyst in the dark. Generally, cationic M.B has strong absorption band centered at 664 nm and another little absorption shoulder band nearly at about 615 nm. With increasing contact time, all the peak intensity is shifted downward or all nanocatalyst, especially for a hybrid DNSA@CS@ MnF2O4 the change is most remarkable (60 min). The enhancement is attributed to the big differences in total surface properties as well as the presence of nitro, amino, hydroxyl and MnFe2O4 which acted as important active sites (Gupta et al., 2017). The adsorption capacities (qe) of the prepared nanocatalyst were determined by the following formula:

Fig. 3. The 3DAFM topography module of (a) DNSA@CS; (b) MnFe2O4; and hybrid DNSA@CS@MnFe2O4 nanocatalyst. 22


K. Shoueir et al.

Table 2 Kinetic parameters for MB adsorption on dark and parameters of L-H model under visible light. Sample coded

Pseudo-first-order

Pseudo-second-order

−1

−1

K1 (min DNSA@CS MnFe2O4 DNSA@CS @ MnFe2O4

)

4.6 × 10 −3 1.7 × 10 −3 0.02 × 10 −3

R12

q

0.79 0.95 0.96

14.2 48.1 112.6

cal

(mg/g)

K2 (g mg

−1

min

)

2.04 × 10−3 0.18 × 10−3 0.02 × 10−3

Intra-particle diffusion R2

2

q

0.91 0.88 0.95

cal.

30.3 47.3 163.8

q

exp.

29.15 46.3 97.6

L-H Kinetics 2

Kid

C

R

0.61 0.10 0.07

5.7 2.9 0.6

0.94 0.95 0.99

Rate constant (min−1)

R2

0.012 0.057 0.093

0.919 0.975 0.982

Langmuir-Hinshelwood model. This data goes well with the obvious crystalline phase of MnFe2O4 in XRD. The presence of DNSA@CS coated MnFe2O4 helped faster degradation. Also, larger surface area (219.36 m2/g) and little particle size generate surface active sites. As a result, the existence of (%OH) on the site increased which leads to a production more (%OH) radicals, the major oxidant necessary for improving the photocatalytic towards photodegradation. Based on the results in Fig. 6c, the relation between photodegradation and contact time prove that the maximum degradation obtained with DNSA@CS@MnFe2O4 after 30 min reaches 94.44%. While 80 min (91.01%) and 40 min (73.9%) for DNSA@CS and MnFe2O4 respectively, is sufficient to attain saturation time and degradation. The results confirming that the nanocatalyst DNSA@CS@ MnFe2O4 combination system, significantly accelerates the degradation of MB under visible light Fig. 4. Decolorization (%) against time for DNSA@CS, MnFe2O4, and DNSA@CS@MnFe2O4 without visible light source.

5.4. Degradation of MB by DNSA@CS@MnFe2O4 hybrid nanocatalyst under different conditions

(Habiba, Islam, Siddique, Afifi, & Ang, 2016). Fig. 4, shows the degree of decolorization (%) of MB against time (min). The estimated decolorization (%) of MB removal for all nanocatalyst exhibited gradual decolorization rate 29.15% within 135 min, 46.38% within 60 min and 80.65% within enough 60 min respectively. Initially, the adsorption enhances the collision between MB and oxidizing species in the surface as time increased till maximum surface area clog up. In the last stages of adsorption, a small diffusion control adsorption of MB into the internal pores. Consequently, the adsorption process became slower.

5.4.1. Influence of pH factor Owing to less sensitivity of DNSA@CS and pure MnFe2O4 towards photocatalytic degradation rather than hybrid DNSA@CS@MnFe2O4. So, this combined system only was used to illustrate the rest parameters. The controlled pH had a strong effect on DNSA@CS@MnFe2O4 nanocatalyst as decolorizer as in Fig. 7a. Generally, in acidic medium (pH 3.0), the degradation rate increased gradually up to 42.2% then the degradation efficiency level off. The hydroxyl, amino, nitro and carboxylic moieties of DNSA@CS carrier were protonated under acidic conditions as the following reaction stated:

5.3. Photocatalytic performance

R-X + H+ → R-XH+ where X may be eOH, eNO2, eNH2, and eCOOH (7)

The photocatalytic degradation of MB was investigated in the presence of hydroxyl radical (%OH) active species using 0.08 M H2O2 scavenger in this experiment. From Fig. 5, it could be seen that the intensity of adsorption peaks diminished gradually as the degradation time increased and blue-shifted MB undergoes complete degradation at 80, 40, and 30 min after light irradiation of DNSA@CS, MnFe2O4, and DNSA@CS@MnFe2O2 respectively. Indicating the potency of H2O2 on the photocatalytic degradation. These results revealed that the azo bonds and the aromatic rings of MB molecule were destroyed under visible light irradiation in the presence of the of the photocatalyst. Our trends are completely consistent with the results obtained by Zhu et al. (Zhu et al., 2014). The standard formula by Langmuir–Hinshelwood (L–H) model was analyzed to comprehend the photodegradation kinetics of the heterogeneously catalyzed reaction. The simplified formula of this model to the apparent pseudo-first-order expressed as follow:

ln(

C ) = −kapp t C0

Presence of MnFe2O4 as the coating material is presumably (+ve) charged in acidic media which unable to provide more −OH groups to generate (%OH) radicals on the surface. Moreover, the nature of MB cationic dye in acidic range doing electrostatic repulsion between MB and nanocatalyst. For these reasons the degradation efficiency decreased. On contrary, at higher pH (̴ 9.0) the degradation ability reaches 98.35%. In alkaline solution, promote higher levels of eOH− groups to yield (%OH) radicals attacked and destroy the target MB. Under pH > 9.5, the surface became (+ve) charged favoring the removal of MB molecule. But, the instability of H2O2 scavenger in alkaline solution led to the formation of ferric hydroxide complexes and reduce (%OH) radicals. Also, Mn2+ ion participate in the chain reaction, forming (HO2%/O2%−). Another considered reason, the reactivity of a high valence iron species Fe3+ less than (%OH) radicals and this might be formed in pure alkaline medium (He, Ji, Wang, & Zhang, 2017; Luo et al., 2010). The following equations support the meaning:

(6)

2H2O2 → 2H2O + O2

−1

Where kapp is the apparent pseudo-first-order constant (min ). Typical plots of ln(C/Co) against time are linear with slope equal to kapp. From Fig. 6a, b and Table 2 it can be seen that the photocatalytic potency of DNSA@CS@MnFe2O4 with kapp value of 0.093 min−1 is higher than DNSA@CS and pure MnFe2O4 systems and all nanocatalyst obeyed

Fe

23

3+

+ H2O2 → Fe

3+

(8) −

+ %OH + OH

Mn

2+

+ %OH → Mn

Mn

3+

+ H2O2 → MnO2+

3+

(9) (10) (11)


K. Shoueir et al.

Fig. 5. UV–vis spectra of M.B dye suspension in contact with (a) DNSA@CS, (b) MnFe2O4, and (c) DNSA@CS@MnFe2O4 nanocatalyst under visible light irradiation.

MnO2+ + H+ ↔ Mn2+ + HO2%/O2%− Fe

3+

−

+ HO2%/O2% → Fe

2+

5.4.4. Stability and reusability of DNSA@CS@MnFe2O4 Economically, the stability of any photocatalyst is a desirable trait for practical applications. The nanocatalyst was isolated using an external magnet, washed and dried before use at 80 °C to attain sapless. Thus, the stability experiment was conducted for five runs under using optimum conditions (contact time, 30 min, H2O2 concentration, 0.16 M, pH factor 9 and dosage 0.06 g/l) for 1hr. Fig. 7d shows the first two recycling runs were performed without any loss of catalytic ability. Beginning from the third run till fifth run plateau, the degree of decolorization reduced to 91.7,84.3 and 83.1%, respectively. Ferrites exhibited paramagnetic character and easily recoverable from catalytic system even after five runs (He et al., 2017; Lou et al., 2017). This expects that DNSA@CS@MnFe2O4 able to eliminate various of pollutants disrupters in wastewater. On the other hand, the modified nanocatalyst was recovered and studied by EDX and SEM (Fig. 7e), which shows that chemical structure, size, and morphology of the nanocatalyst remains unchanged, more indicating their excellent stability.

(12) +

+ O2 + H

(13)

5.4.2. Influence of H2O2 concentration Fig. 7b. Shows the effect of extra H2O2 concentration (0.02, 0.04, 0.08 and 0.16 M) on the photodegradation of MB. The photodegradation efficiency directly proportional to the concentration of H2O2. At low concentration of H2O2, the MB degradation decreased to the lowest rate 74.8% because of there is no sufficient amount of %OH radicals produced anymore. At H2O2 higher concentration (0.16 M) faster reaction proceed due to rapid generation of potent %OH radicals.

5.4.3. Influence of nanocatalyst dosage Fig. 7c. represented the effect of nanocatalyst dosage (0.02, 0.04, 0.08 and 0.1 g/l) on the degradation of MB by DNSA@CS@MnFe2O4. When the nanocatalyst amount increased from 0.02 to 0.04 g/l; the decolorization increased from 93.4 to optimal 98.9%. This powerful efficiency mainly was because of the availability of more active sites, leads to the production of active radical species on the surface of nano photocatalyst (Abdelwahab & Helaly, 2017; He et al., 2017; Rasoulifard, Dorraji, Amani-Ghadim, & Keshavarz-Babaeinezhad, 2016). The efficiency decreased upon increasing the dosage exactly at 0.08 and 0.1 g/l, this may be attributed to blocking and excessive scattering of incident light as catalyst amount increased (El-Kemary, Abdel-Moneam, Madkour, & El-Mehasseb, 2011).

5.4.5. Hot filtration test In order to confirm that the reaction is heterogeneous, a hot filtration test was performed in the model reaction. The model reaction was carried out for 7 min in the presence of magnetic nanocatalyst. At this stage, the degradation of MB was 62.2%. The catalyst was then removed and the filtered reaction mixture was then stirred for another 2 h under the same condition. Fig. 7f reveal that there is no corresponding increase of product yield was observed, suggesting that no homogeneous catalyst was involved. In addition, metal leaching in the catalyst was determined and ICP-AES analysis of the clear filtrate indicated 24


K. Shoueir et al.

Fig. 6. (a) Time course degradation curves, (b) Linear plot of the Langmuir–Hinshelwood model, and (c) photodegradation (%) vs time (min) under visible light irradiation.

that the Mn and Fe contents were 0.03 and 0.2 ppm, respectively. This very slight loss of Mn and Fe species in the filtrate is an outstanding data and indicates potent interact of the bimetallic element species with DNSA@CS and affirm the heterogeneous nature of DNSA@CS@ MnFe2O4 during photo treatment. However, no significant improvement in the degradation percentage of MB was observed after separation of catalyst from the reaction mixture. These results proved that the DNSA@CS@MnFe2O4 hybrid nanocatalyst was stable under the reaction conditions and apparently there was no leaching of the metal content from the magnetic nanostructure.

Mn2+ − OH− + H2O2 → Mn3+ − OH− + %OH

(14)

Mn3+ − OH− + H2O2 → Mn2+ − OH− + %OOH + H+

(15)

Fe2+ − OH− + H2O2 → Fe3+ − OH− + %OH + OH−

(16)

Fe

3+

−

− OH + H2O2 → Fe

2+

−

− OH + %OOH + H

+

(17) 2+

Besides, the synergetic effects of the reducing couples Mn /Mn3+ and Fe3+/Fe2+ cycles (Eqs. (1)–(4)), the reaction is thermodynamically favored, which cyclically benefits from redox cycles given significant catalytic efficiency through repeated internal electron transfer (Divyapriya, Nambi, & Senthilnathan, 2016; He et al., 2017). Accordingly, the different functionality located hybrid DNSA@CS@MnFe2O4 adsorbed MB molecules and promote the electron transport during the catalytic reaction. Also, H2O2 catalyzed to produce a large amount of % OH radicals due to MnFe2O4 anchored on the surface of DNSA@CS which facilitate the degradation of cationic MB structure into CO2, H2O, and minerals. Therefore, the coupling contribution of both DNSA@CS and MnFe2O4 nanocatalyst improves the decomposition of MB molecules.

5.4.6. Exploration of the catalytic mechanism The mechanism of photocatalytic performance for the prepared DNSA@CS@MnFe2O4 nano photocatalyst was presented in Scheme 1b. The remarkable synergistic enhancement of MnFe2O4 and the modified CS is the significant role in photoreactivity. DNAS@CS acting as a bridge between the MnFe2O4 coater and the respective MB molecule. From EDX data the intensity of Fe3+ larger than Mn2+ so during photo treatment Fe3+ reduced to Fe2+ which accelerates the Fe3+/Fe2+ cycle to produce primary catalytic %OH radical helping decomposition of MB molecules (Guo, Zhang, Guo, & Jimmy, 2013). The interaction between most stable oxidation state Mn2+/MnFe2O4 surface and H2O2 also participate in the chain reaction to produce surface-shielded %OH radical which essential for a remarkable increase in the catalytic activity (Ai, Gao, Zhang, He, & Yin, 2013). As a result, the performance of MnFe2O4 is superior rather than individually MnO and Fe2O3 (Peng et al., 2016). Eqs. (14) and (15) and the same case with Fe2+ species on the nanocatalyst surface takes place Eqs. (16) and (17):

5.4.7. The preparation advantages of DNSA@CS@MnFe2O4, rather than reported literature 1. Microwave-assisted hydrothermal able to fabricate DNSA@CS@ MnFe2O4 in a very short time at relatively low temperature and pressure. Consequently, save both times consuming and energy which effects on adsorption/photodegradation performances rather than other reported materials during literature survey (Areerob, 25


K. Shoueir et al.

Fig. 7. (a) Effect of pH on DNSA@CS@MnFe2O4; (b) Normalized changes in MB photodegradation for the addition of extra H2O2 concentration as a function of time; (c) influence of various nanocatalyst dosage; (d) Effect of recyclability on photodegradation and relative decolorization degree (%); (e) EDX and SEM stability after subjected to irradiation; and (f) hot filtration test.

sequestration of MB molecules, improves biocompatibility and allow ease attachment of targeting moieties (Habiba et al., 2016; Xiao, Liang, Chen, & Wang, 2013). Thus, a DNSA@CS@MnFe2O4 promising adsorbent for adsorption and photodegradation in terms of its excellent achievement in magnetization and adsorption decomposition capacity compared with various materials reported in the literature.

Cho, Jang, & Oh, 2018; Fan et al., 2017; Mahmoodi, 2015; Meng et al., 2015) 2. Magnetic isolation is convenient for all sides, however, new DNSA@CS exhibited diamagnetic domain. While DNSA@CS@ MnFe2O4 have powerful magnetization 29.95 Mg (emu/g) comparing with reported magnified CS materials with further modification (Abdelwahab & Ghoneim, 2018; Gautam et al., 2017; Verma, Singh, Ram, Shah, & Kotnala, 2011) 3. Coating MnFe2O4 with a biocomponent like DNSA@CS permits 26


K. Shoueir et al.

6. Conclusions

performance in Suzuki-Miyaura coupling reactions. Carbohydrate Polymers, 181, 596–604. Barbosa-Barros, L., García-Jimeno, S., & Estelrich, J. (2014). Formation and characterization of biobased magnetic nanoparticles double coated with dextran and chitosan by layer-by-layer deposition. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 450, 121–129. Baughman, G. L., & Perenich, T. A. (1988). Fate of dyes in aquatic systems: I. Solubility and partitioning of some hydrophobic dyes and related compounds. Environmental Toxicology and Chemistry, 7(3), 183–199. Bensalah, N., Alfaro, M. Q., & Martínez-Huitle, C. (2009). Electrochemical treatment of synthetic wastewaters containing Alphazurine A dye. Chemical Engineering Journal, 149(1–3), 348–352. Cao, C., Xiao, L., Chen, C., & Cao, Q. (2015). Magnetically separable Cu2O/chitosanFe3O4 nanocomposites: Preparation, characterization and visible-light photocatalytic performance. Applied Surface Science, 333, 110–118. Chen, L., Ma, J., Li, X., Zhang, J., Fang, J., Guan, Y., & Xie, P. (2011). Strong enhancement on Fenton oxidation by addition of hydroxylamine to accelerate the ferric and ferrous iron cycles. Environmental Science & Technology, 45(9), 3925–3930. Cui, W., An, W., Liu, L., Hu, J., & Liang, Y. (2014). A novel nano-sized BiOBr decorated K2La2Ti3O10 with enhanced photocatalytic properties under visible light. Journal of Solid State Chemistry, 215, 94–101. Divyapriya, G., Nambi, I. M., & Senthilnathan, J. (2016). Nanocatalysts in fenton based advanced oxidation process for water and wastewater treatment. Journal of Bionanoscience, 10(5), 356–368. El-Kemary, M., Abdel-Moneam, Y., Madkour, M., & El-Mehasseb, I. (2011). Enhanced photocatalytic degradation of Safranin-O by heterogeneous nanoparticles for environmental applications. Journal of Luminescence, 131(4), 570–576. El-Kemary, M. A., El-mehasseb, I. M., Shoueir, K. R., El-Shafey, S. E., El-Shafey, O. I., Aljohani, H. A., & Fouad, R. R. (2017). Sol-gel TiO2 decorated on eggshell nanocrystal as engineered adsorbents for removal of acid dye. Journal of Dispersion Science and Technology, 1–11. Fan, C., Li, K., Li, J., Ying, D., Wang, Y., & Jia, J. (2017). Comparative and competitive adsorption of Pb (II) and Cu (II) using tetraethylenepentamine modified chitosan/ CoFe2O4 particles. Journal of Hazardous Materials, 326, 211–220. Fang, X., Xiao, J., Yang, S., He, H., & Sun, C. (2015). Investigation on microwave absorbing properties of loaded MnFe2O4 and degradation of Reactive Brilliant Red X3B. Applied Catalysis B: Environmental, 162, 544–550. Farzana, M. H., & Meenakshi, S. (2013). Synergistic effect of chitosan and titanium dioxide on the removal of toxic dyes by the photodegradation technique. Industrial & Engineering Chemistry Research, 53(1), 55–63. Farzana, M. H., & Meenakshi, S. (2015). Visible light-driven photoactivity of zinc oxide impregnated chitosan beads for the detoxification of textile dyes. Applied Catalysis A: General, 503, 124–134. Gautam, S., Shandilya, P., Priya, B., Singh, V. P., Raizada, P., Rai, R., ... Singh, P. (2017). Superparamagnetic MnFe2O4 dispersed over graphitic carbon sand composite and bentonite as magnetically recoverable photocatalyst for antibiotic mineralization. Separation and Purification Technology, 172, 498–511. Gmurek, M., Foszpańczyk, M., Olak-Kucharczyk, M., Gryglik, D., & Ledakowicz, S. (2017). Photosensitive chitosan for visible-light water pollutant degradation. Chemical Engineering Journal, 318, 240–246. Goyal, A., Bansal, S., & Singhal, S. (2014). Facile reduction of nitrophenols: Comparative catalytic efficiency of MFe2O4 (M = Ni, Cu, Zn) nano ferrites. International Journal of Hydrogen Energy, 39(10), 4895–4908. Guo, S., Zhang, G., Guo, Y., & Jimmy, C. Y. (2013). Graphene oxide-Fe2O3 hybrid material as highly efficient heterogeneous catalyst for degradation of organic contaminants. Carbon, 60, 437–444. Gupta, V. K., Saravanan, R., Agarwal, S., Gracia, F., Khan, M. M., Qin, J., & Mangalaraja, R. (2017). Degradation of azo dyes under different wavelengths of UV light with chitosan-SnO2 nanocomposites. Journal of Molecular Liquids, 232, 423–430. Habiba, U., Islam, M. S., Siddique, T. A., Afifi, A. M., & Ang, B. C. (2016). Adsorption and photocatalytic degradation of anionic dyes on Chitosan/PVA/Na-Titanate/TiO2 composites synthesized by solution casting method. Carbohydrate Polymers, 149, 317–331. He, F., Ji, Y., Wang, Y., & Zhang, Y. (2017). Preparation of bifunctional hollow mesoporous Fe0@ C@ MnFe2O4 as Fenton-like catalyst for degradation of Tetrabromobisphenol A. Journal of the Taiwan Institute of Chemical Engineers, 80, 553–562. Herrera, F., Kiwi, J., Lopez, A., & Nadtochenko, V. (1999). Photochemical decoloration of remazol brilliant blue and uniblue a in the presence of Fe3+ and H2O2. Environmental Science & Technology, 33(18), 3145–3151. Houas, A., Bakir, I., Ksibi, M., & Elaloui, E. (1999). Removal of a methylene blue from aqueous solution over the commercial activated charcoal CECA40. Journal de Chimie Physique et de Physico-Chimie Biologique, 96(3), 479–486. Jiao, Y., Wan, C., Bao, W., Gao, H., Liang, D., & Li, J. (2018). Facile hydrothermal synthesis of Fe3O4@ cellulose aerogel nanocomposite and its application in Fentonlike degradation of Rhodamine B. Carbohydrate Polymers, 189, 371–378. Kafshgari, L. A., Ghorbani, M., & Azizi, A. (2017). Fabrication and investigation of MnFe2O4/MWCNTs nanocomposite by hydrothermal technique and adsorption of cationic and anionic dyes. Applied Surface Science, 419, 70–83. Kant, R. (2012). Textile dyeing industry an environmental hazard. Natural Science, 4(1), 22–26. Kazan, S., Tanrıverdi, E., Topkaya, R., Demirci, Ş., Akman, Ö., Baykal, A., & Aktaş, B. (2016). Magnetic properties of triethylene glycol coated CoFe2O4 and Mn0. 2Co0. 8Fe2O4 NP's synthesized by polyol method. Arabian Journal of Chemistry, 9, S1131–S1137. Konstantinou, I. K., & Albanis, T. A. (2004). TiO2-assisted photocatalytic degradation of

In summary, a novel modified CS with DNSA are synthesized for the first time to enlarge the specific surface area and then coupled with MnFe2O4 to produce DNSA@CS@MnFe2O4 nanocatalyst. FTIR prove that strong electrostatic attraction force between MnFe2O4 and DNSA@CS matrix. Anchoring of MnFe2O4 enhances thermal stability to be not more than 4% due to spinal phase nature. The crystal phase of individual pure CS, DNSA@CS, MnFe2O4, and combined and DNSA@CS@MnF2O4 was confirmed by XRD analysis and exhibited successful fabrication of the hybrid nanocomposite. For adsorption of MB, the magnified DNSA@CS@MnF2O4 was better represented by Lagergren- pseudo- first-order kinetics. However, photodegradation kinetics of the heterogeneously catalyzed reaction showed that the hybrid nanocomposite obeyed Lagergren-first-order model. In particular excellent catalytic achievements 98.9% degree of decolorization was obtained under visible light irradiation and within 30 min in the support of H2O2 at R.T. Importantly, the degradation efficiency nearly stopped after removal of catalyst and no leaching detected of the catalytic system. This paper not only offers a green and new approach for the synthesis of novel modified CS by DNSA, but also participate understanding the redox mechanism of manganese ferrite by using heterogeneous photo-Fenton catalyst system. Notes The authors declare no competing financial interest. Appendix A. Supplementary data Supplementary data associated with this article can be found, in the online version, at https://doi.org/10.1016/j.carbpol.2018.05.076. References Abdelwahab, N., & Ghoneim, A. (2018). Photocatalytic activity of ZnO coated magnetic crosslinked chitosan/polyvinyl alcohol microspheres. Materials Science and Engineering: B, 228, 7–17. Abdelwahab, N., & Helaly, F. (2017). Simulated visible light photocatalytic degradation of Congo red by TiO2 coated magnetic polyacrylamide grafted carboxymethylated chitosan. Journal of Industrial and Engineering Chemistry, 50, 162–171. Ahamed, M. A. R., Jeyakumar, D., & Burkanudeen, A. R. (2013). Removal of cations using ion-binding terpolymer involving 2-amino-6-nitro-benzothiazole and thiosemicarbazide with formaldehyde by batch equilibrium technique. Journal of Hazardous Materials, 248, 59–68. Ai, Z., Gao, Z., Zhang, L., He, W., & Yin, J. J. (2013). Core-shell structure dependent reactivity of Fe@ Fe2O3 nanowires on aerobic degradation of 4-chlorophenol. Environmental Science & Technology, 47(10), 5344–5352. Alharbi, S., & El-Sheshtawy, H. (2017). Glycine capped SnO2 nanoparticles: Synthesis, photophysical properties and photodegradation efficiency. Nanoscience and Nanotechnology Letters, 9(3), 266–271. Almasian, A., Chizarifard, G., & Najafi, F. (2017). Mesoporous MgO/PPG hybrid nanofibers: synthesis, optimization, characterization and heavy metal removal property. New Journal of Chemistry. Alnuaimi, M. M., Rauf, M., & Ashraf, S. S. (2007). Comparative decoloration study of Neutral Red by different oxidative processes. Dyes and Pigments, 72(3), 367–371. Areerob, Y., Cho, J. Y., Jang, W. K., & Oh, W.-C. (2018). Enhanced sonocatalytic degradation of organic dyes from aqueous solutions by novel synthesis of mesoporous Fe3O4-graphene/ZnO@ SiO2 nanocomposites. Ultrasonics Sonochemistry, 41, 267–278. Azarudeen, R. S., Riswan Ahamed, M. A., Thirumarimurugan, M., Prabu, N., & Jeyakumar, D. (2016). Synthetic functionalized terpolymeric resin for the removal of hazardous metal ions: Synthesis, characterization and batch separation analysis. Polymers for Advanced Technologies, 27(2), 235–244. Baran, T., & Menteş, A. (2016). Polymeric material prepared from Schiff base based on Ocarboxymethyl chitosan and its Cu (II) and Pd (II) complexes. Journal of Molecular Structure, 1115, 220–227. Baran, T., Menteş, A., & Arslan, H. (2015). Synthesis and characterization of water soluble O-carboxymethyl chitosan Schiff bases and Cu (II) complexes. International Journal of Biological Macromolecules, 72, 94–103. Baran, T., Sargin, I., Kaya, M., & Menteş, A. (2016). Green heterogeneous Pd (II) catalyst produced from chitosan-cellulose micro beads for green synthesis of biaryls. Carbohydrate Polymers, 152, 181–188. Baran, N. Y., Baran, T., & Menteş, A. (2018). Production of novel palladium nanocatalyst stabilized with sustainable chitosan/cellulose composite and its catalytic

27


K. Shoueir et al.

Kinetic studies and artificial neural network modeling. Applied Catalysis A: General, 514, 60–70. Riswan Ahamed, M. A., Azarudeen, R. S., Prabu, N., & Burkanudeen, A. R. (2015). Studies of retention and reusable capacities of melamine formaldehyde based terpolymer against some toxic metal ions by batch equilibrium method. Separation Science and Technology, 50(13), 1925–1939. Rivas, P., Sagredo, V., Rossi, F., Pernechele, C., Solzi, M., & Peña, O. (2013). Structural, magnetic, and optical characterization of ${\rm MnFe} _ {2}{\rm O} _ {4} $ nanoparticles synthesized via sol-Gel method. IEEE Transactions on Magnetics, 49(8), 4568–4571. Sebastian, S., Sylvestre, S., Jayabharathi, J., Ayyapan, S., Amalanathan, M., Oudayakumar, K., & Herman, I. A. (2015). Study on conformational stability, molecular structure, vibrational spectra, NBO, TD-DFT, HOMO and LUMO analysis of 3, 5-dinitrosalicylic acid by DFT techniques. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 136, 1107–1118. Shafiu, S., Topkaya, R., Baykal, A., & Toprak, M. S. (2013). Facile synthesis of PVAMnFe2O4 nanocomposite: Its magnetic investigation. Materials Research Bulletin, 48(10), 4066–4071. Shoueir, K. R., Sarhan, A. A., Atta, A. M., & Akl, M. A. (2016). Macrogel and nanogel networks based on crosslinked poly (vinyl alcohol) for adsorption of methylene blue from aqua system. Environmental Nanotechnology, Monitoring & Management, 5, 62–73. Singh, K., & Arora, S. (2011). Removal of synthetic textile dyes from wastewaters: A critical review on present treatment technologies. Critical Reviews in Environmental Science and Technology, 41(9), 807–878. Stoia, M., Muntean, E., Păcurariu, C., & Mihali, C. (2017). Thermal behavior of MnFe2O4 and MnFe2O4/C nanocomposite synthesized by a solvothermal method. Thermochimica Acta, 652, 1–8. Topkaya, R., Kurtan, U., Baykal, A., & Toprak, M. S. (2013). Polyvinylpyrrolidone (PVP)/ MnFe2O4 nanocomposite: Sol-gel autocombustion synthesis and its magnetic characterization. Ceramics International, 39(5), 5651–5658. Verma, K. C., Singh, V. P., Ram, M., Shah, J., & Kotnala, R. (2011). Structural, microstructural and magnetic properties of NiFe2O4, CoFe2O4 and MnFe2O4 nanoferrite thin films. Journal of Magnetism and Magnetic Materials, 323(24), 3271–3275. Wang, W., Ding, Z., Cai, M., Jian, H., Zeng, Z., Li, F., & Liu, J. P. (2015). Synthesis and high-efficiency methylene blue adsorption of magnetic PAA/MnFe2O4 nanocomposites. Applied Surface Science, 346, 348–353. Xiao, Y., Liang, H., Chen, W., & Wang, Z. (2013). Synthesis and adsorption behavior of chitosan-coated MnFe2O4 nanoparticles for trace heavy metal ions removal. Applied Surface Science, 285, 498–504. Yang, L., Zhang, Y., Liu, X., Jiang, X., Zhang, Z., Zhang, T., & Zhang, L. (2014). The investigation of synergistic and competitive interaction between dye Congo red and methyl blue on magnetic MnFe2O4. Chemical Engineering Journal, 246, 88–96. Yao, Y., Cai, Y., Lu, F., Wei, F., Wang, X., & Wang, S. (2014). Magnetic recoverable MnFe2O4 and MnFe2O4-graphene hybrid as heterogeneous catalysts of peroxymonosulfate activation for efficient degradation of aqueous organic pollutants. Journal of Hazardous Materials, 270, 61–70. Zhao, Y., Tao, C., Xiao, G., & Su, H. (2017). Controlled synthesis and wastewater treatment of Ag 2 O/TiO 2 modified chitosan-based photocatalytic film. RSC Advances, 7(18), 11211–11221. Zhu, H.-Y., Yao, J., Jiang, R., Fu, Y.-Q., Wu, Y.-H., & Zeng, G.-M. (2014). Enhanced decolorization of azo dye solution by cadmium sulfide/multi-walled carbon nanotubes/ polymer composite in combination with hydrogen peroxide under simulated solar light irradiation. Ceramics International, 40(2), 3769–3777.

azo dyes in aqueous solution: Kinetic and mechanistic investigations: A review. Applied Catalysis B: Environmental, 49(1), 1–14. Kumar, S., Nair, R. R., Pillai, P. B., Gupta, S. N., Iyengar, M., & Sood, A. (2014). Graphene oxide-MnFe2O4 magnetic nanohybrids for efficient removal of lead and arsenic from water. ACS Applied Materials & Interfaces, 6(20), 17426–17436. Li, X., Hou, Y., Zhao, Q., & Wang, L. (2011). A general, one-step and template-free synthesis of sphere-like zinc ferrite nanostructures with enhanced photocatalytic activity for dye degradation. Journal of Colloid and Interface Science, 358(1), 102–108. Lin, S. H., & Peng, C. F. (1996). Continuous treatment of textile wastewater by combined coagulation, electrochemical oxidation and activated sludge. Water Research, 30(3), 587–592. Liu, Z., Bai, H., & Sun, D. D. (2011). Facile fabrication of porous chitosan/TiO 2/Fe 3 O 4 microspheres with multifunction for water purifications. New Journal of Chemistry, 35(1), 137–140. Liu, S.-T., Zhang, A.-B., Yan, K.-K., Ye, Y., & Chen, X.-G. (2014). Microwave-enhanced catalytic degradation of methylene blue by porous MFe2O4 (M = Mn: co) nanocomposites: Pathways and mechanisms. Separation and Purification Technology, 135, 35–41. Lou, Z., Cao, Z., Xu, J., Zhou, X., Zhu, J., Liu, X., ... Xu, X. (2017). Enhanced removal of As (III)/(V) from water by simultaneously supported and stabilized Fe-Mn binary oxide nanohybrids. Chemical Engineering Journal, 322, 710–721. Luo, W., Zhu, L., Wang, N., Tang, H., Cao, M., & She, Y. (2010). Efficient removal of organic pollutants with magnetic nanoscaled BiFeO3 as a reusable heterogeneous Fenton-like catalyst. Environmental Science & Technology, 44(5), 1786–1791. Ma, B., Chen, W., Qiao, X., Pan, G., Jakpa, W., Hou, X., & Yang, Y. (2017). Tunable wettability and tensile strength of chitosan membranes using keratin microparticles as reinforcement. Journal of Applied Polymer Science, 134(14). Mahmoodi, N. M. (2015). Manganese ferrite nanoparticle: Synthesis, characterization, and photocatalytic dye degradation ability. Desalination and Water Treatment, 53(1), 84–90. Meng, Y., Chen, D., Sun, Y., Jiao, D., Zeng, D., & Liu, Z. (2015). Adsorption of Cu2+ ions using chitosan-modified magnetic Mn ferrite nanoparticles synthesized by microwave-assisted hydrothermal method. Applied Surface Science, 324, 745–750. Misbah, M. H., Espanol, M., Quintanilla, L., Ginebra, M., & Rodríguez-Cabello, J. C. (2016). Formation of calcium phosphate nanostructures under the influence of selfassembling hybrid elastin-like-statherin recombinamers. RSC Advances, 6(37), 31225–31234. Misbah, M. H., Santos, M., Quintanilla, L., Günter, C., Alonso, M., Taubert, A., & Rodríguez-Cabello, J. C. (2017). Recombinant DNA technology and click chemistry: A powerful combination for generating a hybrid elastin-like-statherin hydrogel to control calcium phosphate mineralization. Beilstein Journal of Nanotechnology, 8, 772. Peng, X., Qu, J., Tian, S., Ding, Y., Hai, X., Jiang, B., ... Qiu, J. (2016). Green fabrication of magnetic recoverable graphene/MnFe 2 O 4 hybrids for efficient decomposition of methylene blue and the Mn/Fe redox synergetic mechanism. RSC Advances, 6(106), 104549–104555. Prado, A. G., Bolzon, L. B., Pedroso, C. P., Moura, A. O., & Costa, L. L. (2008). Nb2O5 as efficient and recyclable photocatalyst for indigo carmine degradation. Applied Catalysis B: Environmental, 82(3–4), 219–224. Priya, B., Shandilya, P., Raizada, P., Thakur, P., Singh, N., & Singh, P. (2016). Photocatalytic mineralization and degradation kinetics of ampicillin and oxytetracycline antibiotics using graphene sand composite and chitosan supported BiOCl. Journal of Molecular Catalysis A: Chemical, 423, 400–413. Rasoulifard, M., Dorraji, M. S., Amani-Ghadim, A., & Keshavarz-Babaeinezhad, N. (2016). Visible-light photocatalytic activity of chitosan/polyaniline/CdS nanocomposite:

28