Fabrication of S-scheme heterojunction consisting of W-doped BiVO4 and biperovskite Cs2AgBiBr6 for photocatalytic degradation of antibiotics.

Photocatalysis technology can degrade organic pollutants in wastewater, improving the ecological environment and protecting biodiversity. The BiVO4 stable chemical properties of BiVO4 make it a robust candidate for photochemical applications. Moreover, its broad light absorption spectrum and optimal band structure further enhance its potential, driving widespread research interest. The introduction of the eco-friendly biperovskite Cs2AgBiBr6 enhanced BiVO4's surface area and visible light absorbance. Simultaneously, the doping process introduces impurities that modify charge transfer pathways, thereby enhancing the separation efficiency of photogenerated electron-hole pairs. When contrasted with pure BiVO4, the W-BiVO4/Cs2AgBiBr6 composite demonstrates superior surface area characteristics and exhibits stronger absorption within the visible light spectrum. Within 40 min after exposure to visible light, the efficiency of W-BiVO4/Cs2AgBiBr6 photocatalyst to degrade ofloxacin (OFX) and meloxicam (MEL) was 93.15 % and 92.70 %, respectively. Based on the toxicity analyses and antimicrobial assays simulated by the software, no highly toxic substances were found in the degradation intermediate products of OFX and MEL. The catalysts' energy band structure and photoelectrochemical properties showed that W-BiVO4/Cs2AgBiBr6 followed the S-scheme heterojunction charge transfer mechanism. By integrating BiVO4 with other semiconductors in the form of S-scheme heterojunctions, this study explores a strategy that may effectively improve photocatalytic efficiency, particularly in pollutant degradation applications.