Egg-box-like CuCoFe-Prussian blue analogues@bismuth oxybromide S-scheme heterojunctions for efficient...

Egg-box-like CuCoFe-Prussian blue analogue@bismuth oxybromide (A2CCF-pbas@BiOBr) S-scheme heterojunction photocatalysts were synthesized by a simple room-temperature coordination-precipitation method. In the composite, A2CCF-pbas provides abundant active sites, while BiOBr broadens visible-light absorption. The synergistic effect of photothermal conversion and efficient charge transfer improves the photocatalytic performance. Under visible light irradiation, the H₂ production rate of A2CCF-pbas@BiOBr reaches 9.70 mmol g^-1 h^-1, which is 16 times higher than that of pure A2CCF-pbas. In addition, the degradation efficiency of ciprofloxacin (CIP) reaches 98.3% within 2 h, about 1.8 times that of pure BiOBr. The enhanced performance is mainly attributed to the egg-box-like multi-metal framework with abundant active sites, the S-scheme heterojunction with strong redox ability and efficient carrier separation, and the improved photothermal conversion capability. Density functional theory (DFT) calculations further confirm the electron redistribution and internal electric field at the interface, supporting the S-scheme charge transfer pathway. This work provides a useful strategy for designing efficient multi-component photocatalysts.