Construction of an S-scheme Bi2S3/CdIn2S4 heterojunction for the photocatalytic generation of methyl formate

Abstract

Photocatalytic reduction of CO₂ to valuable chemicals is one of the important solutions to the problems of global warming and energy shortage. Here, a Bi₂S₃/CdIn₂S₄ S-scheme heterojunction was constructed by a simple solvothermal method, which greatly facilitated the segregation and migration of photogenerated charge carriers. The optimized heterojunction achieved an efficient methyl formate (MF) generation rate (5464 μmol h⁻¹ g⁻¹) in the photocatalytic CO₂/methanol reduction system, which was about 29-fold that of pure Bi₂S₃. The preliminary mechanism of the photocatalytic system over the S-scheme Bi₂S₃/CdIn₂S₄ heterojunction was proposed using in situ technology and experimental comparison. This work provides insights into the application of metal sulfide heterojunctions in the field of MF research and the photocatalytic CO₂/methanol reduction system.