Synthesis And Visible-Light Photocatlysis Performance Research Of WO₃/BiVO₄Composite Photocatalyst

Recently,with the development of chemical industry in our country,a large number of such as rhodamine B toxic water stain into the environment.More illegal businessmen use the stain to process food,it cause great harm to the environment and human body. Researches show that Rhodamine B cannot be remove by traditional sewage treatment process,but can be degraded by photocatalytic technology.When the photon energy is higher than the absorption threshold of light semiconductor,the valence band of the semiconductor electronic interband transition transit from the valence band to the conduction band,and produce light electrons and holes. The adsorption on the surface of the nanoparticles, dissolved oxygen capture electronic form super oxygen anion,and holes will be adsorbed on the surface of the catalyst, hydroxyl ions and water into hydrogen and oxygen free radicals. And superoxide anion and hydrogen and oxygen free radicals have strong oxidizing,the vast majority of oxidation of organic matter to the final product of CO2and H2O.In this paper, the new nano heterojunction photocatalyst is explored,feasible experiment scheme is proposed,the influence factors of photocatalytic process and do some discussion on the reaction mechanism.Compared to other light catalyst, due to its narrow band gap width, high stability, high recovery rate, non-toxic, low cost and other advantages, BiVO4have a more broad application prospects.In this paper, by hydrothermal synthesis method,using Bi (NO3)3-5H2O as source of bismuth,NH4VO3as source of vanadium,PEG-200as surfactant,prepare of the nanoscale bismuth vanadate semiconductor photocatalyst. Analyzes in detail the preparation of the appearance characteristics of temperature, time, PH, light catalyst and catalytic effect, represent the sample with energy spectrum analysis methods, such as X-ray powder diffraction (XRD), scanning electron microscope (SEM), uv-vis diffuse reflection spectroscopy (UV-Vis-DRS) and so on.The results show that,when hot water temperature is200℃, hydrothermal time is six hours, preparation of pH is7, samples of synthesis of bismuth vanadate catalyst has good photocatalytic activity for rhodamine B.The synthesis of semiconductor bismuth vanadate samples for monoclinic crystal phase structure. After300min, visible light irradiation on the decolorization rate can amount to73.8%for the rhodamine B solution.What’s more,take the energy on the photocatalyst composite modification research of BiVO4in this paper.Using the hydrothermal preparation of WO3/BiVO4composite photocatalyst, and the optimization of the synthesis conditions were discussed. And the photocatalytic effect is analyzed.Results show that the WO3/BiVO4compound catalytic activity of photocatalyst with the same method of pure phase BiVO4has obviously improved.Finally the BiV04photocatalytic reaction mechanism is analyzed and discussed.