Preparation and characterization of photocatalytic TiO2 films on functionalized stainless steel

Abstract

In this study, TiO2 was synthesized using controlled hydrolysis of TiCl4, followed by dialysis. We produced a transparent emulsion that was later dried into TiO2 powder. TiO2 photocatalyst films were deposited applying the technique of pulsed electrophoretic deposition, which decreased bubble formation caused by direct current. The substrates were bare stainless steel (SS) and stainless steel pre-functionalized in a conversion bath. Film surface morphology, crystallinity, elemental composition, and wettability were determined using XRD, SEM–EDAX, and contact angle measurements. The mechanical properties were determined by nano-indentation test. The adhesion was investigated using scratch test. The obtained results showed that the TiO2 film over a conversion layer had better adhesion and mechanical properties than TiO2 over bare SS. The optical characteristics of TiO2 films were tested using PL measurement. The photocatalytic decolourization of the amido black-10B dye was studied over TiO2 coating under UV and visible light irradiation. TiO2 film over a conversion layer without heat treatment exhibited the best photocatalytic activity as a result of its crystalline size and three-phase structure as well as the synergetic effect of TiO2 and Fe2O3.