Preparation of TiO?/ITO and TiO?/Ti photoelectrodes by magnetron sputtering for photocatalytic application

Abstract

Two types of immobilized TiO? films with nanostructure, TiO?/ITO conductive glass and TiO?/Ti mesh, were prepared by a radio frequency magnetron sputtering technique, in which a titanium (Ti) target was sputtered in a gaseous mixture of argon and oxygen. The TiO? films were characterized by X-ray diffraction, AFM microscopy, SEM microscopy and photoelectrochemical measurements. Their photocatalytic (PC) activity, photoelectrocatalytic (PEC) activity and electrochemical (EC) activity were evaluated in the degradation of 2,4,6-trichlorophenol (TCP) in aqueous solution. The experiments confirmed that the TiO? films sputtered at 2.0 Pa had relatively high PC activity due to more active sites formed on the surface of TiO? films. The experiments demonstrated that the PEC activity of the TiO?/Ti mesh was better than that of TiO?/ITO, resulting from less impedance between the TiO? film and Ti mesh. Furthermore, the experiments also demonstrated that at a higher anodic potential, the TiO?/Ti mesh exhibited not only a PEC reaction but also an EC oxidation reaction at the backed Ti mesh in the degradation of TCP. This study concludes that the sputtered TiO?/Ti mesh is an effective photoelectrode for achieving an enhanced TCP degradation in such a PEC reaction system.