Tuning interfacial oxygen vacancy level of bismuth oxybromide to enhance photocatalytic degradation of bisphenol A.

Oxygen vacancies (OVs) have garnered significant interest for their role as active sites, enhancing the catalytic efficiency of various catalysts. Despite their widespread application in environmental purification processes, the generation of OVs conventionally depends on high-temperature conditions and strong reducing agents for the extraction of surface partial oxygen atoms from catalysts. In this work, bismuth oxybromide (BiOBr) nanosheets with varying levels of OVs were synthesized via a simple and effective solvothermal method. This novel method affords precise control over the conduction band (CB) and valence band (VB) positions of BiOBr. The presence of different OVs exhibited varying photocatalytic efficiencies in the degradation of bisphenol A (BPA) under visible light irradiation, with higher levels of OVs resulting in superior photocatalytic performance. Furthermore, radical scavenger experiments demonstrated that superoxide oxides (O) and holes (h) were the primary reactive oxygen species for BPA degradation. Additionally, BiOBr-OVs exhibited excellent anti-interference and stability in water matrices containing diverse inorganic anions and organic compounds. This work provides a simple and effective approach for the fine-regulating of catalysts through interfacial defect engineering, paving the way for their practical application in environmental decontamination.