A Simple and Economical Preparation of a TiO₂-Coating Solution by Hydrothermal Reaction

抄録

    A simple and economical preparation of a titanium dioxide (TiO₂)-coating solution by hydrothermal reaction was investigated. An aqueous solution of hydrogen peroxide mixed with TiO₂ fine particles (Degussa P25) was autoclaved at 105–120 °C for 10–40 min, so that the solubility of TiO₂ was found to be significantly improved at 120 °C and over and to greatly affect both the amount of TiO₂ loaded on activated carbon (AC) particles and the stability of an AC-supported TiO₂ film. As a result, the optimal preparation condition was determined to be 120 °C for the temperature and 40 min for the reaction time. The coating solution provided AC particles completely covered with a thin TiO₂ film (TiO₂/AC particles). An 1-m³ air contaminated with toluene at 1ppm (0.04 mmol m^–3) in a reactor with an annular path packed with TiO₂/AC particles revealed that toluene is quickly decomposed to below an undetectable concentration of 0.03 ppm and completely converted to CO₂. This rate of decomposition was almost the same as that by TiO₂/AC particles prepared using a commercially available coating solution, indicating that the coating solution prepared in the present study is useful.