IR SPECTROSCOPY STUDY OF SILVER IONS ADSORBED ON TITANIA (ANATASE)

The state and localization of silver(I) ions adsorbed on titania (anatase) are studied by IR spectroscopy of probe molecules. It is established that the surface hydroxyl groups of the support do not participate in the adsorption of Ag+ and the process leads to blocking of the so-called is-proportional-to-Lewis acid sites characteristic of pure anatase. The reduction of Ag+ leads to liberation of these sites and formation of Ag(o)-clusters. It is proposed that the photocatalytic deposition of silver on anatase proceeds with the participation of c.u.s. oxygen anions situated in the vicinity of Ti4+ is-proportional-to-Lewis acid sites. Some new aspects of the process mechanisms are proposed.