摘要
Ti-Ce, Ti-Si binary and Ti-Ce-Si ternary novel nanocomposite oxide photocatalysts were prepared with cheap inorganic salts TiCI4, Na2SiO3·9H2O and Ce（NO3）3·6H2O as precursors by supercritical fluid drying （SCFD） technology. The catalysts were characterized by means of XRD and TEM. The particle size of nanocomposite oxide photocatalysts synthesized by SCFD method is about 6 - 11 nm, which is smaller than those obtained by common drying method （CD）. The phase transformation from anatase to rutile was inhibited by SCFD technology. The peaks of SiO2 and CeO2 in XRD patterns indicate that a SiO2 amorphorous phase exists in all the samples and CeO2 is well dispersed on the surface of TiO2. The orthogonal test was designed to optimize the preparing conditions. It is found that ceria dop;.ng enhances the photocatalyric activity markedly, and the optimum doping of CeO2 is 0.1%. The thermal stability of photocatalyst can be improved ; the growth of particle-size and the decrease of surface area can be prohibited by doping of SlOe. Heat-treatment is a necessary factor to induce chemistry change of Ti-Si surface. The optimum heat-treating temperature is 600℃. A novel and efficient Ti-Ce-Si ternary nanocomposite was prepared by SCFI） method with strong thermal stability and high photoactivity in the photodegratation of phenol.
Ti-Ce, Ti-Si binary and Ti-Ce-Si ternary novel nanocomposite oxide photocatalysts were prepared with cheap inorganic salts TiCI4, Na2SiO3·9H2O and Ce（NO3）3·6H2O as precursors by supercritical fluid drying （SCFD） technology. The catalysts were characterized by means of XRD and TEM. The particle size of nanocomposite oxide photocatalysts synthesized by SCFD method is about 6 - 11 nm, which is smaller than those obtained by common drying method （CD）. The phase transformation from anatase to rutile was inhibited by SCFD technology. The peaks of SiO2 and CeO2 in XRD patterns indicate that a SiO2 amorphorous phase exists in all the samples and CeO2 is well dispersed on the surface of TiO2. The orthogonal test was designed to optimize the preparing conditions. It is found that ceria dop;.ng enhances the photocatalyric activity markedly, and the optimum doping of CeO2 is 0.1%. The thermal stability of photocatalyst can be improved ; the growth of particle-size and the decrease of surface area can be prohibited by doping of SlOe. Heat-treatment is a necessary factor to induce chemistry change of Ti-Si surface. The optimum heat-treating temperature is 600℃. A novel and efficient Ti-Ce-Si ternary nanocomposite was prepared by SCFI） method with strong thermal stability and high photoactivity in the photodegratation of phenol.
基金
ProjectsupportedbytheNationalDevelopmentProjectofHighTechnology(Project863)(2001AA322030)andtheNationalNaturalScienceFoundationofChina(20076004)
