Facile electrodeposition synthesis of antimony-doped tin dioxide reactive electrochemical membranes for rapid sulfamethoxazole degradation

Antimony-doped tin dioxide reactive electrochemical membranes (ATO-REMs) exhibit robust catalytic activity, yet their large-scale application is hindered by the laborious multi-step synthesis of the conventional sol-gel method. Herein, we propose a facile electrodeposition strategy for fabricating ATO-REMs, involving sequential deposition of Sb and Sn on porous Ti substrates followed by thermal annealing. This method achieved uniform distribution of interconnected ATO clusters with low charge transfer resistance and high electrocatalytic activity. Through systematic analysis of experimental conditions and electrodeposition processes, a comprehensive mechanistic framework was established to elucidate how operating conditions and synthesis parameters influence electrocatalytic performance. By tuning the electrodeposition process, the optimized electrodeposited ATO-REM (EPATO-REM) achieved 99.1% removal of sulfamethoxazole (SMX) during single-pass filtration with a low energy consumption of 0.5 kWh m −3 , outperforming the conventional sol-gel-derived ATO-REM. Further investigations revealed that SMX degradation was driven by •OH oxidation and direct electron transfer, with seven intermediates identified and degradation pathways proposed. Furthermore, EPATO-REMs exhibited oxidation stability during 8-h operation, universal efficacy for diverse contaminants, and practical applicability in complex water matrices. This work provides a facile and scalable alternative to the labor-intensive sol-gel method for ATO-REM fabrication, advancing the development of high-performance REMs for water treatment.