Enhanced photoelectrochemical anticorrosion performance of WO3/TiO2 nanotube composite films formed by anodization and electrodeposition

An ordered TiO2 nanotube film was first fabricated by anodization on a Ti substrate. WO3 nanoparticles were then deposited on the film via potentiostatic electrodeposition with the aim of improving the photoelectrochemical properties of the film. In comparison with the plain TiO2 film, the photoresponse of the WO3/TiO2 nanotube composite film was shown to be enhanced in the visible region. When subjected to white light illumination, the WO3/TiO2 composite film reduced the potential of the coupled 403 stainless steel in a 0.5 M NaCl solution by 370 mV (relative to its corrosion potential), demonstrating a good photoelectrochemical anticorrosion effect. It was found that even after the illumination had been switched off the composite film could provide cathodic protection for 19 h due to its charge storage capability.