Improvement of photocatalytic activity of titania prepared by new methods

In this study，we prepared TiO D22 D2 catalysts for the photo-decomposition of organic compounds. TitaniaD22 D2) particles were prepared by hydrolysis of titanium alkoxide，titanium tetra-n butoxide （TTB）in water-in-oil microemulsion. Crystal size of TiO - D22 - D2 thus obtained was 8.5 nm and muchsmaller than that of commercial TiO D22 TiO D2P-25. The surface area of TiO D22 - D2 was larger than that of commercial TiO D22 - D2 （P-25）because of the small crystal size. In photo-decomposition of acetic acidthe catalytic activity of the TiO - D22 - D2 prepared by this method was higher than that of P-25. thehigh activity was attributed to the high surface area.Moreover，to enhance the catalytic activity for the photo-decomposition of organic compounds ata lowconcentration in waste water，active carbon (AC)-支持TiO - D22 - D2 catalysts were prepared. TTB and phenolic resin were usedas a precursor of TiO D22 D2 and active carbon，respectively. Colloidal TiO D22 - D2 particles were synthesized by hydrolysis of TTB in a methanolsolution of phenolic resin. The phenolic resin containing TiO D22 D2 particles was carbonized inD2 in the temperature range from 400℃to 800℃。Anatase titania with a crystal size ofapproximately 7.0 nm was obtained. photodecomposition of acetic acid was carried out as a modelairactivation was conducted to increase the surface area of carbon support，because the increase in the surface area to the enhancement of the absorbing abilityTiO - D22 - D2 catalyst for acetic acid. The photocatalytic activity was increased with The increasingsurface area。

In this study, we prepared TiOィイD22ィエD2 catalysts for the photo-decomposition of organic compounds. Titania ( TiOィイD22ィエD2) particles were prepared by hydrolysis of titanium alkoxide, titanium tetra-n-butoxide (TTB), in water-in-oil microemulsion. Crystal size of TiOィイD22ィエD2 thus obtained was 8.5 nm and much smaller than that of commercial TiOィイD22ィエD2, P-25. The surface area of TiOィイD22ィエD2 was larger than that of commercial TiOィイD22ィエD2 (P-25) because of the small crystal size. In photo-decomposition of acetic acid, the catalytic activity of the TiOィイD22ィエD2 prepared by this method was higher than that of P-25. The high activity was attributed to the high surface area.Moreover, to enhance the catalytic activity for the photo-decomposition of organic compounds at a low concentration in waste water, active carbon (AC)-supported TiOィイD22ィエD2 catalysts were prepared. TTB and phenolic resin were used as a precursor of TiOィイD22ィエD2 and active carbon, respectively. Colloidal TiOィイD22ィエD2 particles were synthesized by hydrolysis of TTB in a methanol solution of phenolic resin. The phenolic resin containing TiOィイD22ィエD2 particles was carbonized in NィイD22ィエD2 in the temperature range from 400℃ to 800℃. Anatase titania with a crystal size of approximately 7.0 nm was obtained. Photo-decomposition of acetic acid was carried out as a model reaction. Air-activation was conducted to increase the surface area of carbon support, because the increase in the surface area led to the enhancement of the absorbing ability of TiOィイD22ィエD2 catalyst for acetic acid. The photocatalytic activity was increased with the increasing surface area.