Study On Photocatalytic Properties Of Modified Bismuth Vanadate

Nowadays, environmental pollution and energy shortage are two hot topics. The visible-light photocatalytic technology and preparation of materials which can utilize effectively solar energy to realize production of hydrogen using photocatalytic or degradation of pollutants become a hot topic in recent years. BiVO4has got much attention in the field of photocatalysis, due to its narrow bandgap (2.4eV), high utilization efficiency of solar energy and in response to visible-light, BiV04is a new kind of photocatalysts. This paper mainly discusses the photocatalytic properties of modified BiVO4.The pure BiVO4and Ag-BiV04, Cu-BiVO4samples had been prepared by sol-gel method. And we studied the structure and properties of product which were charactered by X-ray diffraction (XRD), Transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), Ultraviolet-visible diffuse reflection spectrum (DRS) and X-ray photoelectron spectroscopy (XPS). To evaluate the visible light catalytic activity of the samples which prepared in different conditions via the decolorization rate of methyl orange.The paper studied the influence of calcination temperature and calcination time on its structure and photocatalytic properties. XRD analysis showed that, when the calcination temperature was500℃, bismuth vanadate was pure monoclinic phase expect trace amount of tetragonal phase; the test of photocatalytic activity confirmed that, the photocatalytic activity of the product which obtained under the condition of500℃and4h was better.Structure, microstructure morphology and photocatalytic properties of Ag-BiVO4and Cu-BiVO4have been studied. XRD analysis showed that the diffraction peaks’ position of Ag. Cu modified samples and pure samples are consistent. TEM analysis indicated that in the Cu-BiVO4system, Cu existed in the form of copper oxide; XPS analysis indicated that in the Ag-BiVO4system, Ag existed in the form of silver oxide; UV-Vis analysis showed that BiVO4band gap reduce significantly after Ag, Cu modified, the absorption in the visible light of samples enhance due to the range of visible light absorption expand, which can strengthen the photocatalytic performance of the bismuth vanadate. So the decolorization rate of methyl orange have been raised in the photocatalytic activity tests.