The Preparation And Photocatalytic Performance Study Of The New Bi-V-O Materials

At present, the contaminated environment and the shortage of energy are theconsiderable serious problems for the humanity. Semiconductor-mediatedheterogeneous photocatalysis using sunlight as energy is a very good outlookingtechnology for depuration without generating harmful by-products.Thephotocatalyst is the significant key for the photocatalysis. However, the utilizationrate of of sunlight and the quantum conversion rate are quitly low for the number ofphotocatalysts. So this is the the bottleneck for the wide application of photocatalytictechnology. Therefore, the search for efficient photocatalysts with responsing tovisible light is becoming a focus in this field.As we all known, material properties play a role on the microstructure. Therefore,the design and preparation of the new photocatalytic material with a special structure,composition, morphology and high surface area are increasingly attracting researchattention. In recent years, the hollow microsphere is a special structure of the materialgroups. The hollow microsphere has been much attracted and by the researchersbecause of its unique characteristics such as the lower density, the higher of specificsurface area, the fine surface permeability and the larger interior space.Against this backdrop, solvothermal preparation, characterization andphotocatalytic properties of the different morphologies of photocatalysts materials aremade a systemic study. Meanwhile, synthesis conditions, morphology contronl, bandstructure, photocatalytic performance and influencing factors were investigated inorder to provide theoretical and experimental basis for designing novel photocatalysts.The main contents of this paper can be divided into two parts:（1）The Bi₄V₂O₁₁hollow microsphere was prepared by solvothermal method. Theinfluence of synthesis conditions which have played important role on the phasestructure and morphologies,such as the reaction time and tempreture,alkali source,pHvalues,the volume ratio between alcohol and ethylene glycol,the addition of urea andthe addition of Bi were investigated.The possible mechanism of Bi₄V₂O₁₁hollowmicrosphere under solvothermal conditions were proposed on the base ofcharacterization results from X-ray diffraction（XRD）, electron microscope（FESEM/TEM）. Compared with other morphologies of the prepared Bi₄V₂O₁₁, theexperimental results show that the photocatalytic properties of the Bi₄V₂O₁₁hollowstructure was best than others. Such outstanding performance was attributed to itshigher surface area and unique particle morphology.（2） The BiVO₄2D flowers-like and special morphologies were prepared bysolvothermal method. The influence of synthesis conditions which have played important role on the phase structure and morphologies,such as the reaction time andtempreture,alkali source,pH values,the volume ratio between alcohol and ethyleneglycol,the addition of urea and the addition agents（pvp and urea）were investigated.The possible mechanism of BiVO₄2D flowers-like under solvothermal conditionswere proposed on the base of characterization results from X-ray diffraction（XRD）,electron microscope（FESEM/TEM）. Compared with other morphologies of theprepared BiVO₄, the experimental results show that the photocatalytic properties ofthe BiVO₄the quadrangular-like structure was best than others. Such outstandingperformance was attributed to its higher surface area and unique particle morphology.