Electronic supporting information Electrochemical performance of Ti3C2Tx MXene in aqueous media: towards ultrasensitive H2O2 sensing
Lenka Lorencovaa1,Tomas Bertoka1, Erika Dosekovaa, Alena Holazovaa, Darina Paprckovaa, Alica Vikartovskaa, Vlasta Sasinkovaa, Jaroslav Filipb, #, Peter Kasakb,*, Monika Jerigovac,d, Dusan Velicc,d, Khaled A. Mahmoude, Jan Tkaca,* a
Institute of Chemistry, Slovak Academy of Sciences, Dubravska cesta 9, Bratislava 845 38, Slovakia b
c
Center for Advanced Materials, Qatar University, P.O. Box 2713, Doha, Qatar
Department of Physical Chemistry, Faculty of Natural Sciences, Comenius University, Mlynska Dolina, Bratislava, 842 15, Slovak Republic d
e
International Laser Centre, Ilkovicova 3, Bratislava 841 04, Slovak Republic
Qatar Environment and Energy Research Institute (QEERI), Hamad Bin Khalifa University (HBKU), P.O. Box 5825, Doha, Qatar * Corresponding author, Jan Tkac, e-mail:
[email protected] * Corresponding author, Peter Kasak, e-mail:
[email protected]
1 These
authors contributed equally. # Current address: Department of Environment Protection Engineering, Tomas Bata University in Zlin, Vavreckova 275, Zlin 762 72, Czech Republic
Fig. S1 CVs performed in 0.1 M PB pH 7.0 at GCE and at GCE/Ti3C2Tx prepared from Ti3C2Tx dispersions sonicated for 1, 10, 30 or 60 min.
Fig. S2 Dependence of laser power on the intensity of Raman spectrum performed using Ti3C2Tx powder. Table S1 Contact angle and free surface energy of Ti3C2Tx or oTi3C2Tx modified surfaces Contact angle [°] Ti3C2Tx oTi3C2Tx Water 36.1 ± 8.4 29.3 ± 0.4 Diiodomethane 51.4 ± 4.3 56.4 ± 8.0 Free surface energy [mJ m-2] Total Dispersive component Polar component
63.0 33.5 29.5
65.8 30.7 35.1
Fig. S3 Ti3C2Tx (left) vs. oTi3C2Tx (right) – contact angle in water (upper row) and in CH2I2 (lower row).
Table S2 Summary of values obtained from AFM measurements Ti3C2Tx Image Surface Area [nm] 254,357 Image Projected Surface Area [nm] 250,000 Image Surface Area Difference [%] 1.7 Image Rq [nm] 1.6 Image Ra [nm] 1.3 Image Rmax [nm] 10.5
oTi3C2Tx 250,132 250,000 0.053 0.20 0.16 1.4
Fig. S4 This is the same AFM image of oTi3C2Tx as shown in Fig. 5 right with zoomed features on the surface with zaxis of 1.4 nm.
Fig. S5 Profile of features on the modified Au chip surface visualized by AFM for Ti3C2Tx (black) and oTi3C2Tx (green) (left image) and 3D visualization of features present on Ti3C2Tx modified Au chip (right image).
Fig. S6 Typical XPS spectra of Ti3C2Tx (black) and oTi3C2Tx (green) modified Au chip, showing decrease of Ti2p and F1s peak intensity for oTi3C2Tx compared to Ti3C2Tx.
Fig. S7: XRD spectrum of Ti3C2Tx deposited on glass from a 1.5 mg mL-1 aqueous dispersion sonicated for 30 min.
Table S3 Summary of values obtained from XPS measurements Composition [atomic %] O1s C1s Ti2p F1s
Ti3C2Tx 29.2 ± 0.9 42.9 ± 0.3 9.2 ± 0.1 18.8 ± 0.5
oTi3C2Tx 29.0 ± 0.8 62.9 ± 5.7 4.4 ± 3.2 3.8 ± 1.7
Fig. S8 SIMS spectrum of Ti3C2Tx in a positive polarity.
Fig. S9 SIMS spectrum of oTi3C2Tx in a positive polarity.
Fig. S10 SIMS spectrum of Ti3C2Tx in a negative polarity.
Fig. S11 SIMS spectrum of oTi3C2Tx in a negative polarity.
Fig. S12 SIMS 2D images for fragments of Ti3C2Tx in a positive polarity.
Fig. S13 SIMS 2D images for fragments of oTi3C2Tx in a positive polarity.
Fig. S14 SIMS 2D images for fragments of Ti3C2Tx in a negative polarity.
Fig. S15 SIMS 2D images for fragments of oTi3C2Tx in a negative polarity.
Fig. S16 CVs with 5 subsequent CV scans were performed in 0.1 M PB pH 7.0 containing 2 mM NADH solution at Ti3C2Tx modified GCE. The sweep rate was set to 100 mV s -1.
Fig. S17 Chronoamperograms for oxidation of 2 mM NADH solution at bare GCE and at GCE/Ti3C2Tx run at a potential value of 700 mV in an electrolyte containing 0.1 M PB pH 7.0.
Fig. S18 CVs assayed in presence of 1 mM H2O2 at bare GCE, GCE/Ti3C2Tx, GCE/oTi3C2Tx and on GCE modified by MXene intercalated with DMSO (i.e. GCE/Ti3C2Tx (DMSO)) or modified by oTi3C2Tx with intercalated DMSO (i.e. GCE/oTi3C2Tx (DMSO)). Electrolyte: 0.1 M PB pH 7.0. The experiments were run at a scan rate of 100 mV s-1.
Fig. S19 Calibration curve for detection of H2O2 on Ti3C2Tx modified GCE constructed from data presented in Fig. 10.
