Multi-channel charge transfer in self-supporting B-g-C3Nx/Bi2S3/CdS dual S-scheme heterojunction toward enhanced photothermal-photocatalytic performance

Improving the charge separation efficiency of catalysts is a significant challenge in photocatalysis. To solve this problem, we design a three-dimensional self-supported B-g-C3Nx/Bi2S3/CdS dual S-scheme heterojunction photocatalytic system mimicking natural photosynthesis to achieve multi-channel rapid charge transfer. The dual S-scheme heterojunction induces double interface electric fields on the surface of ultra-thin B-g-C3Nx nanosheets, which can drive charge carriers to migrate directionally along multiple channels and suppress carrier recombination through spatial separation of electrons and holes. Furthermore, the three-dimensional interconnected open framework of B-g-C3Nx/Bi2S3/CdS enhances light absorption, touching off intense photothermal effects and near-field temperature rise, thereby improving the chemical reaction kinetics. Benefiting from the efficient charge separation and near-field temperature rise, the B-g-C3Nx/Bi2S3/CdS exhibits a photocatalytic oxytetracycline degradation rate of 98.7% and H2 evolution rate of 4.78 mmol g−1 h−1. This work provides new insights into the construction of efficient S-scheme photocatalysts with multiple-channel charge transfer characteristics.