Effect Of SrTiO₃ Modification On Photocatalytic Performance

Photocatalysts use solar energy to degrade pollutants and have the advantages of no secondary pollution,high efficiency,and energy conservation.SrTiO₃ has a suitable forbidden band width and good stability,and is a photocatalytic material with great development potential and application prospect.However,at present,SrTiO₃photocatalyst is confronted with problems such as complicated preparation process,large pollution,high cost,low utilization of visible light,and difficulty in recovery.Therefore,it is of great significance to prepare SrTiO₃ catalysts under environment-friendly,pollution-free and low-cost conditions,and to modify them to improve photocatalytic activity while solving recovery difficulties.In this paper,SrTiO₃ catalysts are modified in two directions.On the one hand,we use chemical solution deposition（CSD）to prepare precursor solutions.After high temperature treatment,LaAlO₃ covered by SrTiO₃ surface is pure and stable.Finally,SrTiO3-LaAlO3 composite material is obtained.This method is unique and novel,and the process is simple and convenient.Then its XRD was used to characterize its structure,and the photocatalytic activity of SrTiO3-LaAlO3 composites was investigated by catalytic degradation of rhodamine B.The results of the study show that we have the best effect of controlling the particle size of barium titanate on No.1 sample,and the degradation rate of 75%can be achieved by UV light irradiation for 3 hours.On the other hand,a La-doped SrTiO₃ catalyst is prepared by a high-temperature solid-state reaction method.The structure and surface properties of the modified SrTiO₃are examined by XRD,SEM and UV-vis.The photocatalytic activity of SrTiO₃ is investigated by catalytic degradation of rhodamine B.The results show that the crystal structure of the La-doped SrTiO₃ samples changes from the cubic system of SrTiO₃toward the monoclinic system of La₂Ti₂O₃;La doping makes the bandgap of SrTiO₃sample decrease,but the bandgap width is reduced to a limited extent,which can not reach the visible light response range,so its absorption of ultraviolet light is improved,and the absorption of visible light has little effect.;The higher the content of La-doped,the more Sr in the substitutional SrTiO₃ lattice,the better the photocatalytic ability of SrTiO₃ samples.