Carbon Doping and Oxygen Vacancy-Tungsten Trioxide/Cu₃SnS₄ S-Scheme Heterojunctions for Boosting Visible-Light-Driven...

Developing ideal photocatalysts for energy regeneration and environmental remediation by combining the advantages of individual semiconductors remains a significant challenge. Herein, tungsten trioxide (WO₃)/Cu₃SnS₄ S-scheme heterojunction composite photocatalysts are developed. Initially, doped oxygen vacancy (OV) was prepared on two-dimensional WO₃ nanosheets by direct calcination method. Subsequently, Cu₃SnS₄ nanoflowers are produced via a one-step hydrothermal process, which are then used to wrap the WO₃ nanosheets. The close contact between WO₃ and Cu₃SnS₄, coupled with unsaturated C-OV coordination, enhanced the interfacial electron transport. Under visible light irradiation, the WO₃/Cu₃SnS₄ shows an impressive H₂ production rate of 3345.26 μmol h^-1 g^-1, a significant improvement over the individual performances of WO₃ and Cu₃SnS₄. Moreover, WO₃/Cu₃SnS₄ demonstrated the highest photocatalytic tetracycline degradation efficiency, achieving 99.4% degradation within 90 min of illumination. An efficient S-scheme heterojunction system with a well-aligned band structure was successfully constructed. This design effectively extends their lifetime, allowing the heterojunction to achieve maximum efficiency in the light reaction.