Study On Preparation And Photocatalytic Properties Of Visible Light Response Bismuth Vanadate

Nowadays, environmental pollution and energy issues are challenges andneed to be solved urgently. Therefore, photocatalytic technology and the newphotocatalytic materials which can utilize solar energy effectively to realize theproduction of hydrogen or degradation of organic pollutants become a researchdirection in recent years. BiVO4is a new kind of visible-light responsivephotocatalysts in the field of photocatalysis. It has many advantages such asnarrow bandgap, easy preparation and in response to visible-light. While in thephotocatalytic reaction, the poor carrier transmission efficiency of BiVO4limitsits photocatalytic property. And this paper mainly discusses the modification andthe photocatalytic performance of BiVO4.The BiVO4powder and BiVO4/RGO composites were prepared by thehydrothermal method. We studied the structure and the properties of preparedproducts by X-ray diffraction (XRD), Scanning electron microscopy (SEM),Fluorescence emission spectra (PL) and Ultraviolet-visible diffuse reflectionspectrum (DRS). We evaluated the catalytic activity of the sample via thedecolorization rate of Methylene blue. We prepared the monoclinic bismuthvanadate with regular shape (pH=6,180℃), and the intensity of the emissionspectrum and the electron hole recombination rate are the lowest.The paper studies the influence of the RGO on its structure, morphology andphotocatalytic properties. XRD pattern shows that the addition of RGO did notdestroy the structure of BiVO4. From SEM we can see that (010) crystal plane ofBiVO4. PL analysis shows that the intensity of the emission spectrum decreasedsignificantly, the delocalization of the big π bond as a large electron acceptor, thephotogenerated electrons move to the graphene surface, and then improve thecatalytic activity of photocatalytic materials. Methylene blue decolorization rateof BiVO4/RGO increased significantly than pure BiVO4. In this paper, boron-doped BiVO4photocatalysts is synthesized by sol-gelmethod. Boron-doped BiVO4was analyzed by XRD, XPS, TEM, and DRS forstudying the structure, morphology and properties. From XRD pattern we can seethat the diffraction peak appears no significant changes after doped the boronelement. Furthermore, there is no other peaks other than monoclinic BiVO4. TEManalysis shows that the crystallinity of Boron-doped BiVO4increased comparedwith the pure BiVO4. The increasing grain size match well with the reducedmaximum FWHM of (112) diffraction peak. The observed B1s peak located at192.3eV from XPS analysis, it is due to the interstitial B in the BiVO4lattice. Inaddition, when the amount of boron is up to3.0at%, a negative shift of Bi4f7/2peak and a positive shift of O1s appeared. This is due to the interstitial B ionswith positive charge in the BiVO4. The photoelectric property was analyzed byLSV, ABPE and EIS. We find that the photocurrent density of B doped BiVO4(0.6at%) photoanode are11times than pure BiVO4, and its charge transferimpedance is the lowest.