Oxygen vacancies nanoarchitectonics in BiVO4/WO3 heterostructured photoanode for effective berberine wastewater purification and electricity generation

Background Photoanode, as a key component of the photocatalytic fuel cell, still faces challenges for high-efficiency wastewater treatment and synchronous electricity generation, owing to low electron-hole separation efficiency and light response. Methods Oxygen vacancies were rationally introduced on BiVO4/WO3 (OV-BiVO4/WO3) as visible-light-responsive photoanode, through a simple two-step hydrothermal method. The favorable activities were primarily derived from the synergistic effects of the oxygen vacancies and heterojunction, which extended the light adsorption range and significantly improved the separation ability of photogenerated carriers, revealing by comprehensive experiments and theoretical calculations. Significant Findings Compared with WO3, BiVO4 and BiVO4/WO3, OV-BiVO4/WO3 exhibited highest berberine degradation rate (97.7 %, 120 min) and maximum power density (0.42 mW cm−2). Further, the influence of water conditions on photocatalytic performance was explored considering the complexity of actual wastewater. The findings evidenced that ·OH and ·O2− mainly participated in antibiotic decomposition. The photocatalytic reaction mechanism and berberine degradation pathway over OV-BiVO4/WO3 were proposed. This study emphasizes the importance of oxygen vacancies engineering controlling over the surface catalytic performance of photoelectrode and electricity generation, and illustrates the potential of for water remediation and energy production.