Research Of Preparation And Photocatalytic Properties Of Titanate

Strontium titanate with perovskite structure is a kind of new functional material. Inthe field of photocatalysis, as a perovskite compound with high stability and suitableband gap energy(Eg), strontium titanate is known to be a typical photocatalyst for theoverall decomposition of water and photocatalytic degradation of organic substances.Strontium titanate has high research potential and wide application foreground.In this paper, strontium titanate has been investigated. Using Sr(NO3)2andTi(OBu)4as raw materials, strontium titanate powder was prepared by the sol-gelprocess. The effect of some factors such as the molar ratio of Sr to Ti and calciningtemperature were investigated. By analyzing the influencing factors, the optimumsynthesis conditions were determined. The advances in modification of strontiumtitanate were explored. Porous SrTiO3and the strontium titanate photocatalyst dopedwith rare earth metal were synthesized. In the preparation procedure, the effect offactors, such as different templates, addition amount of PEG4000, dosage of ion anddoping of different metals on the properties of the photocatalyst were investigated toescertain the optimal synthetic condition. By means of Scanning Electron Microscope(SEM), X-ray Diffraction (XRD), Brunaure-Emmett-Teller Analysis (BET), X-rayPhotoelectron Spectroscopy (XPS) and Fourier Transform Infrared (FT-IR), thecharacteristics and structure of the as-prepared strontium titanate powder were analyzed.The catalytic activity was investigated by decomposing of methyl orange.The conclusions of the paper were as follows.1) In the preparation procedure ofSr2TiO4, the molar ratio of Sr to Ti and calcining temperature are key factors. Afterbeing calcinated for3h at800℃, the as-prepared Sr2TiO4with even granule, favorableperformance and high degree of crystallinity possessed high photocatalytic activitieswhen the molar ratio of Sr to Ti was1:1.2) Porous SrTiO3have larger specific surfaceand higher degree of crystallinity than that of Sr2TiO4. The photocatalytic experiment results indicated that templates and addition amount of PEG4000were the key factors todetermine the photocatalytic activities of the samples. The catalytic performance ofporous SrTiO3were preferable with quantity of1.5g PEG4000.3) The photocatalyticperformance of strontium titanate was improved greatly by doping La3+among thephotocatalysts doped with rare earth metals. La was incorporated into the lattice of thesynthesized strontium titanate crystals. The doped strontium titanate had larger surfacearea, which can contribute to improve photocatalytic activity. Therefore, a siutableelement for doping is very important. The strontium titanate photocatalyst doped with5%La possessed high photocatalytic activities.