PREPARATION OF ULTRA-FINE TIO2 PARTICLES DISPERSIBLE IN ORGANIC-SOLVENTS AND THEIR PHOTOCATALYTIC PROPERTIES

Ultra fine TiO2 particles which dispersed in various organic solvents were synthesized through hydrolysis of a titanium alkoxide to form col loidal TiO2 particles, followed by modification of the colloidal parti cles with a hydrophobic coupling agent, The organic solvent solutions of the synthesized TiO2 particles were transparent and had high colloi dal stability. Photochemical properties of the TiO2 particles in organ ic solvents were studied: namely how Ti3+ species were formed in the p articles and accumulated in them; and how the particles were photocata lytically active for oxidation of I- and reduction of methylene blue a nd Ag+. From comparative studies of the photocatalytic reactions, the TiO2 particles are found to have higher photocatalytic activity than c ommercially available anatase and rutile ponders.