Enhanced photocatalytic degradation of pollutants over Ni(OH)2/Bi12O17Br2 S-scheme heterostructure with amorphous/crystalline interface

Constructing an S-scheme heterojunction presents an effective strategy to enhance photocatalytic efficiency via accelerating photoexcited charge separation while preserving strong redox potentials. Herein, amorphous Ni(OH) 2 (a-NH) was in-situ integrated with crystalline Bi 12 O 17 Br 2 (BOB) nanosheets to form an amorphous/crystalline a-NH/BOB S-scheme heterojunction. The as-synthesized a-NH/BOB-0.5 photocatalyst exhibited superior bisphenol A (BPA) degradation efficiency, achieving 48.7 and 3.7-fold enhancements compared to individual a-NH and BOB, respectively. Comprehensive investigations revealed that the improved photocatalytic activity originated from the synergistic effects of enhanced light-harvesting ability and the formation of strong interfacial electric field at the amorphous/crystalline interface. Moreover, the influences of solution pH, coexisting anions, and water matrices on BPA degradation efficiency were also investigated. Reaction mechanism and toxicity assessment demonstrated that BPA could be gradually transformed into small molecules with low toxicity. This work demonstrates an efficient approach for the design of high-performance photocatalysts for environmental remediation by constructing amorphous/crystalline interface and S-scheme charge transfer mechanism.