Photoelectrocatalytic degradation of organic pollutants in aqueous solution using a Pt-TiO?film

Abstract

A series of Pt-TiO? films with nanocrystaline structure was prepared by a procedure of photodeposition and subsequent dip-coating. The Pt-TiO? films were characterized by X-ray diffraction, scanning electronic microscope, electrochemical characterization to examine the surface structure, chemical composition, and the photoelectrochemical properties. The photocatalytic activity of the Pt-TiO? films was evaluated in the photocatalytic (PC) and photoelectrocatalytic (PEC) degradation of formic acid in aqueous solution. Compared with a TiO? film, the efficiency of formic acid degradation using the Pt-TiO? films was significantly higher in both the PC and PEC processes. The enhancement is attributed to the action of Pt deposits on the TiO? surface, which play a key role by attracting conduction band photoelectrons. In the PEC process, the anodic bias externally applied on the illuminated Pt-TiO? films can further drive away the accumulated photoelectrons from the metal deposits and promote a process of interfacial charge transfer.