A novel preparation of Bi2O3 and their potent photocatalytic activity under visible-light irradiation

Abstract

Three phases of Bi2O3 were first synthesized by extraction-stripping-precipitation and post decomposition from BiCl3 leaching solution. The as-prepared Bi2O3 were characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectra (FT-IR), scanning and transmission electron microscopy (SEM, TEM), UV-vis diffuse reflectance spectroscopy (UV-vis DRS), Brunauer-Emmett-Teller (BET) and X-ray photoelectron spectroscopy (XPS). The photocatalytic performances of the oxides were investigated by decomposing rhodamine B (RB) under visible irradiation. It shows that the Bi2O3 with different crystal structures and morphology were obtained under different decomposition temperature. The band gaps of as-prepared samples were 2.36, 2.41, and 2.78 eV for β-Bi2O3, α-Bi2O3, and δ-Bi2O3, respectively, and the photocatalytic activities followed the order: β-Bi2O3 > α-Bi2O3 > δ-Bi2O3, which was in good accordance with the photoluminescence spectra measurement results. The β-Bi2O3 exhibited the best photocatalytic performance which can effectively degrade 99.23% RB within 240 min.