Decoration of rutile TiO2 nanorod film with g-C3N4/SrTiO3 for efficient photoelectrochemical cathodic protection

A highly efficient g-C3N4/SrTiO3 co-decorated rutile TiO2 nanorod composite film photoanode was fabricated on a conductive glass substrate by a three-step synthesis process involving hydrothermal reactions and chemical vapor deposition. The g-C3N4/SrTiO3/TiO2 composite film with an appropriate cascade energy band structure showed greatly improved visible light absorption and exhibited 4.5 times higher photocurrent density than the undecorated TiO2 film, resulting from its higher separation and transfer efficiency of the photogenerated electron-hole pairs. Under the white light irradiation, the composite film photoanode made the potential of the coupled 403 stainless steel in a 0.5 M NaCl solution decrease by 680 mV from its free corrosion potential, showing a significantly enhanced photoelectrochemical cathodic protection effect.