Synthesis of a novel one-dimensional BiOBr–Bi4O5Br2 heterostructure with a high quality interface and its enhanced visible-light photocatalytic activity

Abstract

Herein, a novel rod-like BiOBr–Bi₄O₅Br₂ heterostructure with a high quality interface was synthesized by calcining a BiOBr precursor in air at 450 °C for 2 h. Bi₄O₅Br₂ nanosheets grew on the rod-like BiOBr made of nanosheets. The content of the loaded Bi₄O₅Br₂ can be controlled by adjusting the concentration of glucose during the preparation of BiOBr precursors. The photocatalytic activity of the as-made products was evaluated by the degradation of rhodamine B (RhB). The results show that the BiOBr–Bi₄O₅Br₂ heterostructure displays outstanding photocatalytic activity as compared to the pure phase BiOBr and Bi₄O₅Br₂, and 100% RhB (20 mg L⁻¹) can be degraded within 5/10 min under solar/visible-light irradiation. This enhanced photocatalytic performance is ascribed to the synergistic effect of the suitable band alignment of BiOBr and Bi₄O₅Br₂ and the formation of a high quality interface between BiOBr and Bi₄O₅Br₂. Radical scavenger experiments prove that the photogenerated holes and ˙O₂⁻ play a key role in the photodegradation process. This study would offer a simple route for the design and fabrication of one-dimensional junction structures with high interface quality for photocatalytic applications.