Oxygen vacancy-mediated BiVO4/Bi3O4Br S-scheme heterojunction for enhanced photocatalytic degradation of antibiotics

Abstract

Overuse of antibiotics has triggered severe water pollution issues. A novel S-scheme heterojunction nanocomposite, BiVO₄/Bi₃O₄Br, was designed and successfully synthesized in this work, which exhibits superior performance in degrading fluoroquinolone antibiotics (gatifloxacin hydrochloride (GAT) and lomefloxacin hydrochloride (LOM)) and tetracycline antibiotics (tetracycline hydrochloride (TCH)). The construction of the S-scheme heterojunction structure and the incorporation of oxygen vacancies (OVs), which furnish vital channels at the interfaces for the efficient migration of photogenerated carriers, are primarily responsible for the enhanced photocatalytic efficiency of BiVO₄/Bi₃O₄Br. Furthermore, the possible degradation routes of GAT were thoroughly explored, and the photocatalytic degradation mechanism of BiVO₄/Bi₃O₄Br was comprehensively elucidated. This study highlights the combined action of S-scheme heterojunctions and OVs in boosting photocatalytic performance, thus providing a fresh perspective for developing OVs-rich S-scheme heterojunction photocatalysts for wastewater treatment.