Tuning the physico-chemical properties of BiOBr via solvent adjustment: towards an efficient photocatalyst for water treatment

Abstract

BiOBr photocatalysts were prepared by a facile one-pot solvothermal approach with cetyltriethylammnonium bromide and bismuth nitrate as the precursors in ethanol, ethylene glycol, tert-butanol, benzyl alcohol, and 2-methoxyethanol solvents, respectively. The morphology, pore structure, specific surface areas, and optical properties of BiOBr are solvent dependent, and a possible formation mechanism for the thin BiOBr nanosheets prepared in benzyl alcohol with higher exposed (001) facet is proposed. BiOBr prepared in benzyl alcohol exhibited superior photocatalytic activity for the photodegradation of Rhodamine B under visible light irradiation, and the high photocatalytic performance can be ascribed to the nanosheet structure and increased number of exposed (001) surfaces. The photogenerated holes h⁺ and superoxide radical anions ˙O₂⁻ have a major effect on RhB degradation via photocatalysis and dye self-sensitization. This work provides a simple method to prepare BiOBr with a nanosheet structure and more exposed (001) surfaces, which motivates its practical application for the exploitation and utilization of solar energy.