抄録
Allophane-TiO2 composites as highly adsorptive photocatalysts were prepared by dispersing nanoparticles of the natural clay mineral, allophone, into a titanium alkoxide solution by the sol-gel method. During the photocatalytic degradation of trichloroethylene using the allophane-TiO2 composites, emission of the intermediate product, phosgene, was significantly inhibited. Trichloroethylene was transformed into the intermediate product, phosgene, on the TiO2 during the UV irradiation. This compound was rapidly adsorbed by the allophane. The compounds were gradually degraded after diffusing to the TiO2. Although the degradation rate of the trichloroethylene using the allophane-TiO2 composites was slower than that using TiO2, their activity was improved by heating at 400-500 °C.
