Synthesis, characterization and photocatalytic activity of visible-light plasmonic photocatalyst AgBr-SmVO4

Abstract

A novel composite photocatalyst AgBr-SmVO4 was synthesized by deposition method and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and UV–vis diffuse reflectance spectroscopy (DRS). The XRD, TEM, and XPS results indicated the prepared sample was actual a three-phase composite: SmVO4, AgBr, and Ag during the photocatalytic reaction. Due to the plasmon effect of Ag nanoparticles, the composite exhibited excellent photoabsorption ability for visible light. The photoelectrochemical measurement verified that the suitable band potential of AgBr and SmVO4 and the existence of metal Ag resulted in the high efficiency in charge separation of the composite. Photocatalytic degradation of rhodamine B (RhB) was carried out to evaluate the photocatalytic activity of AgBr/SmVO4 under visible-light irradiation. The composite presented excellent photocatalytic activity due to the synergetic effect of SmVO4, AgBr, and Ag nanoparticles. The photocatalytic activities of AgBr-SmVO4 were differently affected by the AgBr content in the catalyst, AgBr-SmVO4 amount, initial RhB concentration, and light sources. The highest degradation rate of 0.150min−1 was obtained on the 50wt% AgBr-SmVO4 sample, which was respectively 3.8 times and 25 times higher than that of AgBr and SmVO4 photocatalyst. It was found that O2− and Br0 acted as the main reactive species for the degradation of RhB under visible-light irradiation.