CuO/BiVO₄Visible Light Responsible Composite Photocatalytic Preparation And Its Photocatalytic Degradation Property

Monoclinic scheelite structure BiVO4was a new visible light responsive photocatalyst, and it had good photocatalytic degradation property to methylene blue (MB) and other organic pollutants. In order to improve photocatalytic capability of BiVO4and develop composite photocatalyst which have higher photocatalytic capability, this thesis focuses on the following works.Novel visible-light responsible monoclinic scheelite structure photocatalysts BiVO4and CuO/BiVO4were prepared by citric acid complexometry using Bi(NO3)3·5H2O, NH4VO3and Cu(NO3)2.3H2O as raw materials. The as-prepared nanopowders were characterized by XRD、XPS、SEM、TEM、DSR、PL and UV-Vis.The CuO/BiVO4composite photocatalyst which was prepared in optimal preparation conditions was used to degrade methylene blue in aquaous solution, in which the effects of initial concentration of methylene blue, pH value of initial solution, photocatalys dosage and H2O2were investigated.The result showed that monoclinic scheelite structure BiVO4can be prepared by citric acid complexometry. The photocatalytic activity of BiVO4was the highest, when the ratio of n(C6H8O7)/n[Bi(NO3)3·5H2O] was2:1, the calcinated temperature was500℃and the calcinated time was4h. The absorption edge of the as synthesized sample is525nm. After dopping with copper, the crystal remained the monoclinic scheelite structure; the absorption edge of catalyst produced a red shift. When Cu-doped concentration is0.2at%, the MB removal rate is above88%under150min visible-light irradiation, which is higher by20%than that of pure BiVO4. This composite had better photocatalitic degradation capacity when be in alkaline condition and photocatalys dosage was1g/L. Using CUO/BiVO4in the degradation of MB, the reaction is accordance with the langmuir adsorption and the first order reaction kinetics.