Boosting charge transfer of BiOBr/AgBr S-scheme heterojunctions via interface Br atom co-sharing for enhanced visible-light photocatalytic activity

Efficient interfacial charge transfer and robust interfacial interactions are crucial for achieving the superior spatial separation of carriers and developing efficient heterojunction photocatalysts. Herein, BiOBr/AgBr S-scheme heterojunctions are synthesized via the co-sharing of Br atoms using an ion-exchange approach, which involves the in-situ growth of AgBr nanoparticles on the surfaces of BiOBr nanosheets. It is revealed that successful construction of a high-quality interface with strong interactions via Br atom bridge between BiOBr and AgBr, which provided a rapid migration channel for charge carriers. In addition, in-situ XPS, Kelvin probe force microscopy, and electron spin resonance evaluations confirmed the establishment of an S-scheme charge-transfer pathway in this tightly contacted heterojunction, which could efficiently prevent the recombination of photogenerated carriers while retaining carriers with a high redox capacity. Finally, the photocatalytic test confirmed that the BiOBr/AgBr heterojunction showed excellent photocatalytic performance and wide applicability thanks to the construction of high quality heterojunction. Overall, this work highlights the importance of rational design of heterogeneous interfaces at the atomic level in photocatalysis, and contributes to rationally design BiOBr-based S-scheme heterojunctions photocatalytic materials with high quality atomic co-sharing interfaces.