An S-Scheme CeO2/Bi2O2S heterojunction photoanode for the photoelectrocatalytic degradation of sulfamethoxazole in synthetic and real wastewater

We prepared an S- scheme heterojunction photoanode using cerium oxide (CeO2) and bismuth oxysulfide (Bi2O2S) for the photoelectrocatalytic degradation of sulfamethoxazole. The CeO2 /Bi2O2S photoanode was synthesised via an in-situ hydrothermal method, ensuring strong contact and efficient charge transfer between the CeO2 and Bi2O2S. The materials and photoanode were characterized with XRD, XPS, photoluminescence, and photoelectrochemistry. The S-scheme configuration observed in the formation of heterojunction in CeO2 /Bi2O2S photoanode was responsible for the improved photoelectrocatalytic performance for the visible light-assisted degradation of sulfamethoxazole. Operational parameters such as the effect of pH and current density were examined. The extent of sulfamethoxazole mineralisation was calculated to be 72 % using the total organic carbon (TOC) measurement. The LC-MS analysis was used to predict the degradation pathway and products. Furthermore, the photoelectrocatalytic efficiency of the CeO2/Bi2O2S photoanode was investigated in real wastewater matrices with TOC removal of 54 %. Therefore, the S scheme CeO2/Bi2O2S photoanodes lends itself to photoelectrochemical water treatment applications.