A novel Bi-based oxybromide BaBiO2Br: Synthesis, optical property and photocatalytic activity

A novel Bi-based layered photocatalyst BaBiO2Br was successfully prepared by a solid-state reaction. The as-prepared samples were characterized by XRD, SEM, DRS, PL and FT-IR. The calcination temperature was found to play an important role in controlling synthesis of BaBiO2Br, and pure BaBiO2Br can only be obtained at 800–900 °C. BaBiO2Br with an indirect optical band-gap of 2.93 eV possess photoabsorption ability in both ultraviolet (UV) and visible light regions. The valence band (VB) were mainly occupied by O 2p and Br 4p orbitals, and the conduction band (CB) was composed of Bi 6p orbital. The photodecomposition of rhodamine-B (RhB) experiments revealed that BaBiO2Br can be used as an effective photocatalyst under UV light and visible light irradiation (λ > 400 nm). The sample calcinated at 700 °C exhibited the highest photocatalytic activity among the obtained BaBiO2Br samples, which may be due to the formation of a heterostructure. Among the obtained pure BaBiO2Br, the sample calcinated at 900 °C possesses higher photocatalytic activity than that prepared at 800 °C for its more surface hydroxyl groups at 900 °C.