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 BiVO 4 with rich oxygen vacancies (OVs) oriented on reduced graphene oxide (rGO) photocatalyst (W-BiVO 4-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, BiVO 4 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 photo-generated charge carriers. The introduction of rGO enlarged the specific surface area, expanded the light absorption range, and promoted the charge transfer of BiVO 4 . OVs both narrowed the band gap and enhanced the generation of O 2 − . W doping and OVs both enhanced the interactions between BiVO 4 and rGO. The CIP degradation rate constant of W-BiVO 4-x /rGO photocatalyst was 1.73, 5.32, 6.43, and 10.70 times higher than those of W-BiVO 4 /rGO, BiVO 4 /rGO, W-BiVO 4 , and BiVO 4 , respectively. Besides, W-BiVO 4-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.