Construction of a Bismuthene/CsPbBr3 Quantum Dot S-Scheme Heterojunction and Enhanced Photocatalytic CO2 Reduction

The CO2 photoreduction process is becoming a promising strategy to solve the energy shortage problem and global warming in recent years. How to promote the separation of photoinduced carriers has attracted attention for the improvement of photocatalytic CO2 reduction. In the present work, an S-scheme heterojunction of Bismuthene/CsPbBr3 quantum dots (Bismuthene/CsPbBr3 QDs) is constructed as the photocatalyst for CO2 conversion. As a result, Bismuthene/CsPbBr3 QDs exhibit an optimal CH4 evolution rate of 43.1 μmol h–1 g–1 with 84.53% selectivity over CH4 under ultraviolet–vis light (UV–vis) irradiation. Construction of the S-scheme heterojunction with a narrow band gap semiconductor is the main factor for improving the photocatalytic performance, as the S-scheme heterojunction can suppress the recombination of photoinduced carriers and retain redox ability. The narrow band gap semiconductor Bismuthene can enhance light absorption abilities. This work probably provides some insights for the designing of heterojunction photocatalysts and the improvement of photocatalytic performance.