Lavender-like S-scheme WO3/ZnIn2S4 heterostructures for boosting photocatalytic degradation of tetracycline

The environmentally friendly disposal of antibiotic wastewater has elicited widespread concern. Herein, lavender-like WO3/ZnIn2S4 heterostructures are constructed by in-situ anchoring ZnIn2S4 nanosheets onto WO3 nanorods and applied to the photocatalytic degradation of tetracycline (TC). When ZnIn2S4 and WO3 are successfully coupled at a molar ratio of 0.3:1, the resultant product WZ-3 exhibits optimal photocatalytic performance, which is 4.7 and 1.5 times higher than that of WO3 and ZnIn2S4, respectively. Such an improvement is originated from the enlarged specific surface area, increased light harvesting, and effective carriers separation facilitated by the formation of an S-scheme heterojunction, which is corroborated through density functional theory (DFT) calculations and experimental characterizations. Moreover, this study elucidates the mechanism governing TC degradation, including its degradation pathways.