Abstract

The effects of the incorporation of Ti3C2Tx nano-sheets (MXenes) on the microstructure of SnO2/Ti electrodes and their electro-oxidation catalytic activity for the degradation of methyl red is studied in this work. MXenes-SnO2/Ti electrodes are fabricated by spin-coating followed by a thermal treatment under ambient atmospheric conditions using a solution containing MXene nano-sheets, SnCl2, citric acid and ethylene glycol as precursor. Energy-dispersive X-ray spectroscopy, Raman spectroscopy and X- ray diffraction analyses of the MXenes-SnO2/Ti electrodes surface indicate the formation of SnO2-TiO2 films with Ti4+ ions incorporated into the lattice of SnO2 crystals. Cyclic voltammetry curves demonstrate that the oxygen evolution reaction is restrained by the MXenes-SnO2/Ti electrodes, while the methyl red electro-oxidation is enhanced – with kinetics following a pseudo-first-order model – compared to the performance of (pure) SnO2/Ti electrodes. These results suggest that oxygen vacancies are formed in the crystal lattice of MXenes-SnO2/Ti electrodes, which act as charge carriers and increase the electrical conductivity of SnO2 as confirmed by the lower charge transfer resistance of MXenes- SnO2/Ti electrodes determined by electrochemical impedance spectroscopy analysis.