Environment-friendly and efficient electrochemical degradation of sulfamethoxazole using reduced TiO2 nanotube arrays-based Ti membrane coated with Sb-SnO2

This study focused on the preparation, characterization, and sulfamethoxazole (SMX) removal performance of the SnO 2 -coated reactive electrochemical membrane (REM). This REM was fabricated by loading SnO 2 on the reduced TiO 2 nanotube arrays (RTNA)-based Ti membrane (TM). Regarding the dopant for SnO 2 , Sb was more effective in boosting the electrocatalytic activity than Bi, and the energy consumption for Sb-SnO 2 -coated REM (TM/RTNA/ATO) was lower than Bi-SnO 2 -coated REM (TM/RTNA/BTO). As for the internal layer, RTNA provided TM/RTNA/ATO with more electroactive surface areas and prolonged the service lifetime. Compared with batch mode, the SMX removal efficiency in flow-through mode was increased up to 8.4-fold. The SMX degradation performances were also affected by fluid velocity, current density, initial SMX concentration, and electrolyte concentration. The synergistic effects of • OH oxidation and direct electron transfer were responsible for the effective removal of SMX. TM/RTNA/ATO was proved to be stable and durable by multi-cycle and accelerated lifetime tests. Its extensive applicability was verified with high removal efficiencies of SMX in the surface water and wastewater effluent. These results demonstrate the promise of TM/RTNA/ATO for water treatment applications.