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

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.