Insight into a novel microwave-assisted W doped BiVO4 self-assembled sphere with rich oxygen vacancies oriented on rGO (W-BiVO4-x/rGO) photocatalyst for efficient contaminants removal

A novel W doped BiVO4 with rich oxygen vacancies (OVs) oriented on reduced graphene oxide (rGO) photo-catalyst (W-BiVO4-x/rGO) was developed by a simple one-step microwave hydrothermal method for efficient removal of ciprofloxacin (CIP) and chlortetracycline (CTC) under visible light. The synergistic effect of W doping, BiVO4 with OVs, and rGO on the enhancement of photocatalytic activity was clarified from experimental and Density Functional Theory (DFT) calculations results. W doping significantly improved the density of photogenerated charge carriers. The introduction of rGO enlarged the specific surface area, expanded the light absorption range, and promoted the charge transfer of BiVO4. OVs both narrowed the band gap and enhanced the generation of center dot O-2. W doping and OVs both enhanced the interactions between BiVO 4 and rGO. The CIP degradation rate constant of W-BiVO4-x/rGO photocatalyst was 1.73, 5.32, 6.43, and 10.70 times higher than those of W-BiVO4/rGO, BiVO4/rGO, W-BiVO4, and BiVO4, respectively. Besides, W-BiVO4-x/rGO photocatalyst prepared by microwave hydrothermal method exhibited higher photocatalytic activity and better combination between materials. This study offers a new strategy to address the problem of antibiotic residues in wastewater.

Automated summary

A novel W-doped BiVO4 with rich oxygen vacancies oriented on reduced graphene oxide (rGO) photocatalyst was prepared, showing significantly enhanced photocatalytic activity due to the synergistic effect of W doping, BiVO4 with OVs, and rGO. W doping increased photogenerated charge carrier density, rGO expanded surface area and light absorption range, and OVs narrowed band gap and enhanced O-2 generation. The CIP degradation rate constant of W-BiVO4-x/rGO was significantly higher than other photocatalysts, demonstrating its potential for addressing antibiotic residues in wastewater.