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 degreesC 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 degreesC 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.