Photoelectrochemical characterization of TiO₂ coatings derived from commercial sol solution for cathodic protection applications

Preliminary photoelectrochemical characterization of TiO₂ coatings made using a commercial sol solution on indium–tin oxide glass substrates was carried out under aerated conditions. The sample with TiO₂ coating without heat treatment yielded the most negative open-circuit potential on ultraviolet illumination, while the 400°C heat-treated sample gave the maximum photocurrent. Both properties are desirable for photocathodic protection applications. A TiO₂ coating, when directly applied on copper plate and processed under similar conditions as that of ITO, however, showed p-type behavior on ultraviolet illumination though a copper plate electrically coupled to ITO glass coated with TiO₂ showed lowering of electrode potential on ultraviolet illumination. The reasons for the above observations are discussed.