Construction of an In₂O₃/Bi₂S₃ Z-Scheme Heterojunction for Enhanced Photocatalytic CO₂ Reduction

Photocatalytic conversion of CO₂ to hydrocarbon fuel is a potential strategy to solve energy shortage and mitigate the greenhouse effect. Here, direct Z-scheme heterojunction photocatalysts (In₂O₃/Bi₂S₃) without an electron mediator are prepared by a simple hydrolysis method. The In₂O₃/Bi₂S₃ composite photocatalysts show greatly boosted photoactivity on CO₂ conversion to CO compared with the pristine In₂O₃ and Bi₂S₃. The highest CO evolution rate of 2.67 μmol·g^-1·h^-1 is achieved by In₂O₃/Bi₂S₃-3, without any sacrificial agent or cocatalyst, which is about 3.87 times that of In₂O₃ (0.69 μmol·g^-1·h^-1). The boosted photocatalytic performance of In₂O₃/Bi₂S₃ composite catalysts can be ascribed to the establishment of a Z-scheme heterojunction, improving the photoabsorption and facilitating charge separation and transfer. This study provides a reference for designing and fabricating high-efficiency Z-scheme heterojunction photocatalysts for photocatalytic CO₂ reduction.