Preparation optimization of multilayer-structured SnO2-Sb-Ce/Ti electrode for efficient electrocatalytic oxidation of tetracycline in water

In this study, electrodeposition and thermal decomposition were alternatively used for the fabrication of a series of novel multilayer-structured SnO2-Sb-Ce/Ti (SSCT) electrodes, and their physiochemical and electrochemical properties were investigated for electrochemical oxidation of tetracycline (TC) in aqueous medium. Experimentally, after the SnO2-Sb-Ce (SSC) composite was electrodeposited for 120s on the titanium substrate in aqueous solution, the outer thermal coatings composed of SSC were synthesized by a hydrothermal method. Both influences of electrodeposition time (T-ed) and thermal decomposition time (T-td) were investigated to obtain the optimum preparation. It was found that when increasing T-ed to a certain extent a longer lifetime of electrode can be achieved, which was attributed to a more solid interlayer structure. A notable SSCTTed,(Ttd) electrode, i.e., SSCT3,10, which was prepared through three times of 120 s' electrodeposition (T-ed = 3) and ten times of thermal decomposition (T-td = 10) obtained the highest oxygen evolution potential 3.141 V vs. SCE. In this selected electrode, when 10 mg.L-1 initial TC concentration was added to this wastewater, the highest color removal efficiency and mineralization rate of TC were 72.4% and 41.6%, respectively, with an applied electridty density of 20 mA.cm(-2) and treatment time of 1 h. These results presented here demonstrate that the combined application of electrodeposition and thermal decomposition is effective in realization of enhanced electrocatalytic oxidation activity. (C) 2018 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. All rights reserved.