Properties of Peroxotitanium Acid Solution and Peroxo-Modified Anatase Sol Derived From Peroxotitanium Hydrate

In order to develop new preparation methods of peroxotitanium acid solution and peroxo-modified anatase sol which are useful for the low-temperature formation of photocatalytic thin films, peroxotitanium hydrate was used as a precursor of them. The formation of the transparent peroxotitanium acid solution was achieved by mixing concentrated H2O2 and peroxotitanium hydrate, which was precipitated by adding ammonia solution into a mixture of diluted TiCl4 aqueous solution and H2O2 solution. The homogeneous and translucent peroxo-modified anatase sols were directly obtained by heating above 70°C the peroxotitanium hydrate suspended in water. The sizes of anatase crystals in the sols were close to that in other peroxo-modified anatase sol obtained by heating at 100°C peroxotitanium acid solution, but the anatase films prepared from the peroxo-modified anatase sol obtained by heating peroxotitanium hydrate showed higher photocatalytic oxidation rates of gaseous isopropanol to acetone.