Preparation of TiO₂/ITO and TiO₂/Ti photoelectrodes by magnetron sputtering for photocatalytic application

Abstract

Two types of immobilized TiO₂ films with nanostructure, TiO₂/ITO conductive glass and TiO₂/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 TiO₂ 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 TiO₂ films sputtered at 2.0 Pa had relatively high PC activity due to more active sites formed on the surface of TiO₂ films. The experiments demonstrated that the PEC activity of the TiO₂/Ti mesh was better than that of TiO₂/ITO, resulting from less impedance between the TiO₂ film and Ti mesh. Furthermore, the experiments also demonstrated that at a higher anodic potential, the TiO₂/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 TiO₂/Ti mesh is an effective photoelectrode for achieving an enhanced TCP degradation in such a PEC reaction system.