“One stone four birds” design atom co-sharing BiOBr/Bi2S3 S-scheme heterojunction photothermal synergistic enhanced full-spectrum photocatalytic activity

The rational design of heterostructure photocatalysts holds significant scientific and technical importance for maximizing the utilization of solar energy. In this study, a full spectrum-responsive S-scheme BiOBr/Bi2S3 heterojunction with co-sharing Bi atoms had been successfully constructed using an ion exchange approach accompanied by an in-situ growth process. Theoretical calculations and advanced techniques analysis demonstrate that the interfacial co-sharing of Bi atoms and the internal electric field (IEF) between BiOBr and Bi2S3 can greatly enhance S-scheme charge transfer, leading to effective spatial charge separation and the maintenance of maximum redox capacity. Additionally, the incorporation of Bi2S3 and the formation of oxygen vacancies (OVs) significantly increased NIR absorption and enhanced the photothermal property, further improving charge separation and utilization. As a result, the optimal photoreduction of Cr(VI) performance in BiOBr/Bi2S3 reached 100% within 10 min of full-spectrum light irradiation, and the CO yield was 20.32 µmol∙g–1 after 5 h of irradiation, which were 31.97 and 3.07 times higher than those of BiOBr, respectively. Furthermore, we elucidated the mechanism of Cr(VI) removal using DFT. This work provides valuable guidance for the rational design and construction of Bi-based S-scheme heterojunction photocatalysts with high-efficiency photocatalytic performance and effective solar light utilization.