Investigation of Photocathodic Porotection Properties of TiO2/WO3 Coatings Prepared by Sol-Gel

Titania (titanium oxide) is one the compositions that is photo-activated under UV radiation. It is shown the adding of tungsten oxide improves this property at the artificial light. In this research، the titanium sol was made by alkoxide precursor. Sodium tungstate di-hydrate was used as tungsten oxide precursor. Sodium tungstate di-hydrate was added to titanium sol in different percentage. Dip-coating method was used by means of preparation of coatings on 316L stainless steel substrate. Crystal structure and morphology of the coatings was investigated by XRD and FE-SEM، respectively. Bound characterization of coatings was carried out by FTIR. Potentiometery method and tafel polarization tests were used to characterization of photocathodic protection properties of coatings. The XRD results showed that the entrance of tungsten oxide into titania structure decreases its crystallites size. In the other hand، the FE-SEM results indicated that the tungsten oxide addition improves the coatings morphology. The bond between the Ti-O and W-O have confirmed by FTIR investigations. In addition، it was observed that the increase of weight percentage of tungsten oxide improves the photocathodic protection properties of coatings.