The Study Of Light Absorption Charateristics Of Doped Complex Oxide With Perovskite Stucture

Photocatalysis can be used to decompose water and is effective for degradation of environmental pollutants, which provides an effective way to produce hydrogen and solve environmental problems by using solar energy. Attention all over the world had been paid on the core materials of photocatalyst, while most of these materials were a wide band gap semiconductor, which was active only under ultraviolet light. As photocatalysts, the perovskite oxides has been paid a great attention and been extensively studied because of its special structure. In this paper, SrTiO₃ was chosen as activity model, and the influence of doping different ions and their radius, electronic configuration, electronegativity on the light absorption character and photocatalytic activity of SrTiO₃ was studied. The detailed contents are as follows:â‘ According to ionic radius and ionic valence, Bi³⁺, Pb²⁺ etc. were chosen to dope in A bit and Co²⁺, Cu²⁺ etc. in B bit. The samples were synthesized by sol-gel method, and the influence of preparation conditions on phase was studied.â‘¡XRD, SEM and Uv-vis were used to analyze SrTiO₃, and the results showed that the doped samples were pure phase of SrTiO₃ perovskite, the particle size of the doped samples was about 100nm and the light absorption activity of the samples ,which were doped with different ions, was enhanced, and the range of absorption wavelength was extended with different degree. A remark increase of the light absorption activity of the samples doping Bi³⁺ in A site and Co²⁺ in B site was detected, and the light with the wavelength of 700nm was also absorbed.â‘¢the photocatalytic activity of the photocatalysts was evaluated by decolorizing rate of methyl orange and rhodamine B under the High-pressure mercury lamp and iodine tungsten lamp light. Results showed that the photocatalytic activity was improved with different degree after doping different metal ions. When A site was doped with Bi³⁺ and B site with Co²⁺, the decolorization rate of SrTiO₃ increased 5～6 times compared with that without doping any ions and photocatalytic activity was detected under visible light.