Visible light driven antibiotics degradation using S-scheme BiWO/CoInS heterojunction: Mechanism, degradation pathways and toxicity assessment.

S-scheme heterojunction photocatalysts with strong redox ability and excellent photocatalytic activity are highly desired for photocatalytic degradation of pollutants. Herein, S-scheme BiWO/CoInS heterojunctions were synthesized using hydrothermal method. The photo-induced carriers transfer mechanism of the S-scheme BiWO/CoInS heterojunction was clarified by band structure analysis, ultraviolet photoelectron spectrometer (UPS), electron spin resonance (ESR) and radical trapping experiments. Significant enhance of light absortion, and more efficient carriers separation were observed from the BiWO/CoInS with CoInS nanoclusters growing on the surface of petal-like BiWO nanosheets. TC degradation efficiency of 90% was achieved by BiWO/CoInS (15:1) within 3 h of irradiation, and ·Oand ·OH radicals were dominated contributors. Possible decomposition pathways of TC were proposed, and ECOSAR analysis showed that most of the intermediates exhibited lower ecotoxicity than TC. This work provides reference on the constructing ternary-metal-sulfides-based S-scheme heterojunctions for improving photocatalytic performance.