Few-layer WS2 modified BiOBr nanosheets with enhanced broad-spectrum photocatalytic activity towards various pollutants removal

Herein, an efficient broad-spectrum WS 2 /BiOBr heterostructure with ultrathin nanosheet was successfully prepared by one-pot hydrothermal route. The self-assembled flower-like WS 2 /BiOBr nanostructure was formed by few-layer WS 2 and BiOBr nanosheets. The optimized heterojunction presented broad-spectrum high-efficiency photocatalytic activity towards the removal of various pollutants under visible-light irradiation, including organic dyes, antibiotics and phenols. This efficiency was linked to high light harvesting combined with effective charge separation/transfer. Meanwhile, the degradation efficiencies varied with nature of the pollutant decreased in the following order: LR5B (99%) > MNZ (97%) >  TC (92%) >  OTC (92%) >  RhB (90%) > CIP (83%) >  MB (78%) > MO (62%) >  bisphenol (42%) > phenol (40%). The photocatalytic process of ciprofloxacin was explored, and the results indicated that high ciprofloxacin concentrations, low pH values and elevated concentrations of ions (PO 4 3− , HPO 4 2‐ , H 2 PO 4 − , and Cu 2+ ) restrained the photocatalytic performances. Trapping experiments and ESR revealed the significant contribution of holes (h + ) in the mechanism, where both superoxide radicals ( O 2 − ) and hydroxyl radicals ( OH) acted as assistants. Overall, this work could offer a new protocol for the design of highly efficient heterostructure photocatalysts for environmental remediation.