Novel Pd/BiVO4 composite photocatalysts for efficient degradation of methyl orange under visible light irradiation

Novel Pd/BiVO4 visible light driven composite photocatalysts were synthesized by the impregnation method. The as-prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and UV-vis diffuse reflectance spectra (DRS). The photocatalytic activities of the Pd/BiVO4 samples were determined by oxidative decomposition of methyl orange in aqueous solution under visible light irradiation. The results indicated that the Pd/BiVO4 photocatalysts were monoclinic phase and consisted of quatrefoil-like and sphere particles. The DRS spectra showed that the composite samples greatly improved the ability of visible light absorption, the absorption edge shifted to red light. XPS results revealed that the doped Pd species existed in the form of palladium oxide. The photocatalytic experiments exhibited enhanced photocatalytic activities for methyl orange degradation under visible light irradiation. The mechanism of enhanced photocatalytic activities of Pd/BiVO4 samples was discussed in this paper. (c) 2007 Elsevier B.V. All rights reserved.