Co/Ce-modified PbO2 as the active layer in Ti/Sb2O3-SnO2/PbO2 electrodes for efficient degradation of crystal violet

In this work, a series of Ti/Sb2O3-SnO2/Co-Ce-PbO2 anodes were successfully prepared by electrodeposition and applied for electrocatalytic oxidation of crystal violet (CV). Studies have shown that introducing Co/Ce can improve the dense microstructure and the preferential growth of crystal planes of the active layer PbO2, which are beneficial to enhance electrocatalytic activity and service life of the electrode. By optimizing the molar ratio of Co:Ce, an anode with excellent reversibility is obtained at 1:2.The CV can be effectively decolorized (99.69% within 150 min) and the corresponding TOC removal is 44.29% under optimum condition with Na2SO4 as electrolyte, current density of 50 mA cm(-2) and initial CV concentration of 15 mg L-1. Both .OH and SO4- are the main reactive species for CV degradation, .OH is mainly generated by electrochemical oxidation, while SO4- with higher oxidizing ability and longer lifetime comes from the oxidation of the adsorbed SO42- by center dot OH.