Enhanced photocatalytic degradation by higher exposure of {110} facet and surface oxygen vacancies of BiOBr through cobalt doping strategy

• Published in: Colloids and surfaces. A, Physicochemical and engineering aspects Physicochemical and engineering aspects, 2024-04, Vol.687, p.133402, Article 133402
• Main Authors: Zhao, Rui, Li, Juexiu, Sun, Maiqi, Shi, Qixu, Zhao, Mingzhu, Li, Miaomiao, Bi, Zixuan, Lei, Xinrui, Jia, Jinping
• Format: Article
• Language: English
• Subjects: Co-doped BiOBr; Density functional theory; Oxygen vacancies; Photocatalytic
• ISSN: 0927-7757; 1873-4359
• DOI: 10.1016/j.colsurfa.2024.133402

Transition metal cobalt doped BiOBr (Co-BOB) was successfully synthesized by using hydrothermal method. The optimized Co-BOB achieved a remarkable rhodamine B degradation rate of 97 % in 30 min under visible light irradiation when initial concentration was 80 mg·L−1. Satisfactory removal efficiency was also observed under ambient sunlight irradiation and various water conditions. The cobalt doping strategy induced abundant surface oxygen vacancies formation (43.22 %) and resulted in an increasing exposure of {110} facets. The photosensitization and photocatalytic activities of Co-BOB significantly enhanced comparing with that of pure BiOBr. The synergy of Co doping and oxygen vacancies also induced the formation of a new band structure in Co-BOB. The synergistic effect promoted the efficient separation of photogenerated electrons and holes. By combining with density functional theory calculation, the RhB photocatalytic degradation mechanism by Co-BOB was proposed. [Display omitted] •Trace amounts of cobalt contributed to the formation of abundant surface oxygen vacancies in BOB.•The photocatalytic degradation efficiency of Co-BOB under visible light irradiation achieved 97 % for 80 mg·L−1 RhB solution.•DFT calculation indicated that the mid-energy levels of Co-BOB were induced by cobalt atoms and oxygen vacancies.