Study of the surface states and activity of a Pt/TiO2 photocatalyst

This paper deals with the correlation of surface states and photoactivity of a Pt/TiO2 catalyst prepared by means of photoreduction of ptCl(6)(2-) on anatase nano-TiO2 powders. Conductivity 6 measurements of pressed powders and XPS were applied in analysis of the surface states energy levels and chemical states of Pt at the nano-TiO2 surface, respectively. The results revealed a new surface state with the energy level of 0.35 eV, lower than the conduction band edge of TiO2. According to the XPS analysis, the new surface state can be attributed to the Pto clusters deposited on the surface of TiO2 particles. The photoactivity of the as-prepared Pt/TiO2 catalyst was characterized by photodecoloration of brilliant red X-3B in aqueous solution. The experimental results indicated that the photoactivity of the Pt/TiO2 catalyst is much higher than that of TiO2. The surface Pt-0 clusters possibly function as trapping centers of generated electrons, resulting in the promotion of photocatalytic activity.