Constructing an S-scheme heterojunction by integrating In-doped BiOBr with mesoporous C3N4 for enhanced photocatalytic performance

S-scheme heterojunction photocatalysts are highly regarded for their effective charge separation and strong redox properties, making them promising for pollutant remediation. This study successfully developed In-doped BiOBr (BOB)/mesoporous g-C₃N₄ (MCN) heterojunctions through a straightforward perovskite transformation method. The In-doped BOB demonstrated superior photocatalytic performance in the degradation of Rhodamine B (RhB) compared to pure BOB. This improvement is attributed to enhanced light-harvesting capabilities, increased charge separation, and efficient interfacial charge transfer. Under simulated sunlight, the In-doped BOB/MCN composite achieved a remarkable 99 % degradation of RhB (20 mg·L⁻¹, 20 mL) within 5 min, outperforming both BOB and MCN. The observed enhancement is due to the synergistic effects of In doping and the formation of the S-scheme heterojunction. Furthermore, In-doped BOB/MCN demonstrated excellent stability. The S-scheme charge transfer pathway was validated through extensive characterization techniques, including XPS and EPR, which confirmed the effective separation of photoinduced charge carriers and the retention of highly active redox electron-hole pairs. This research offers a straightforward strategy for developing novel S-scheme photocatalysts, providing valuable insights for environmental applications and advancing the field of photocatalysis.