Synthesis and photocatalytic performance of Ag-loaded β-Bi 2O 3 microspheres under visible light irradiation

Abstract

The visible-light-driven photocatalyst Ag/β-Bi 2O 3 microspheres were synthesized by a simple chemical method. First, β-Bi 2O 3 microspheres were obtained by a thermal treatment of sphere-like Bi 2O 2CO 3 precursor at 360 °C for 3 h in air and then Ag nanoparticles were in situ incorporated into β-Bi 2O 3 microspheres by impregnation method. The as-synthesized samples were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), UV–vis spectroscopy and photoluminescence measurements. The experimental results demonstrated that the visible light absorption of β-Bi 2O 3 photocatalyst is greatly enhanced with the incorporation of Ag nanoparticles. The SEM and TEM observations revealed that the Ag nanoparticles can be homogenously incorporated in the β-Bi 2O 3 microspheres. The photocatalytic activity of Ag/β-Bi 2O 3 sample was evaluated by the photodegradation of the Rhodamine-B under visible light irradiation as a function of Ag content. It is found that the photocatalytic efficiency of β-Bi 2O 3 can be significantly improved with the incorporation of Ag nanoparticles up to 2.0 wt% Ag. The mechanism for the enhanced photocatalytic activity is also presented.