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

• Published in: The Science of the total environment 2019-12, Vol.694, p.133756-133756, Article 133756
• Main Authors: Fu, Shuai, Liu, Xianming, Yan, Yunhui, Li, Li, Liu, Haiping, Zhao, Fengying, Zhou, Jianguo
• Format: Article
• Language: English
• Subjects: BiOBr; Few-layer; Heterostructure; Photocatalytic degradation; WS2
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2019.133756

Herein, an efficient broad-spectrum WS2/BiOBr heterostructure with ultrathin nanosheet was successfully prepared by one-pot hydrothermal route. The self-assembled flower-like WS2/BiOBr nanostructure was formed by few-layer WS2 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 (PO43−, HPO42‐, H2PO4−, and Cu2+) restrained the photocatalytic performances. Trapping experiments and ESR revealed the significant contribution of holes (h+) in the mechanism, where both superoxide radicals (O2−) 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. [Display omitted] •Facile synthesis of flower-like WS2/BiOBr heterojunction was presented.•Formation process of flower-like WS2/BiOBr heterojunction was proposed.•WS2/BiOBr exhibited broad-spectrum photocatalytic activity towards pollutants.•The environmental factors on the degradation of CIP were investigated.•A plausible photocatalytic mechanism was proposed.