Study On The Modification Of SrTiO₃ And The Photocatalytic Property

Treating various contaminations by photocatalytic redox is an important subject with practical value and it has attracted considerable attention. Its advantage is high efficiency, economy and no secondary pollution.Compounds with the perovskite structure have interesting chemical and physical properties in such fields as electromagnetic, gas sensitivity, photocatalysis, electrochemical activity, and their properties changes substantially with various kinds of molecules or ions in the structure. In the field of photocatalysis, as a perovskite compound, SrTiO₃, is known to be a typical photocatalyst for the overall decomposition of water into H₂ and O₂. In this paper, a series of photocatalysts(SrTiO₃) were prepared by sol-gel method and their photocatalytic activities of NO_x degradation were studied. At the same time, the samples were characterized by UV-Vis spectrophotometer(UV-Vis),X-ray diffraction(XRD) and Scanning Electron Microscopy(SEM). The conclusions of the paper show:1. The performance of the catalyst determined by the light source, the initial concentration of Methylene blue and the shape of the reactor.2. Under the irradiation of UV and Vis, behaviors of SrTiO₃ were improved greatly by doping Zr⁴⁺ ions. And It is noteworthy that the best doping concentration up to 8%, much higher than other ions doping. At this doping concentration, the hehavior of photocatast improved about 4 times.3. Under the irradiation of UV and Vis, doping La²⁺ and V⁵⁺ at one time can also improve the photocatalytic efficiency greatly. The best doping concentration of V⁵⁺ and La²⁺ is 1.5% and 0.5%. We found that the Influence of V⁵⁺ much more than La²⁺.4. Doping many metal ions will reduce the photocatalytic properties, such as Cu and Mn.5. Under the UV light irradiation, Comparison catalytic efficience of all photocatalyst prepared by sol-gel method, the ranking procedure is: Sr_0.999La_0.001Ti_0.920Zr_0.08O₃>Sr_0.995La_0.005Ti_0.985V_0.015O₃>Sr₁La₀Ti_0.995Ni_0.005O₃>Sr₁La₀Ti_0.995Mo_0.005O₃>Sr_0.99La_0.01Ti_0.999Fe_0.001O₃>Sr_0.995La_0.005Ti₁Cu₀O₃>Sr_0.999La_0.001Ti_0.999Zn_0.001O₃>Sr_0.995La_0.005Ti₁Mn₀O₃.