Chromium-doped titanium oxide nanotubes grown via one-step anodization for efficient photocathodic protection of stainless steel

Abstract

Single-step anodization of titanium foils in ethylene glycol based electrolytes , which contain chrome alum (KCr(SO 4 ) 2 ) as the source of chromium, has been used to synthesize chromium doped TiO 2 nanotubes with efficient photocathodic protection of 403 stainless steel. Chrome alum is a non-toxic source of Cr 3+ ions. In addition, the effect of various chrome alum concentrations in the anodizing solution on the photocathodic protection behavior have also been investigated. Chrome alum concentration in the electrolyte affected the performance of the prepared photoelectrodes. The photocurrent density of the best chromium doped TiO 2 nanotube electrode was up to 2.4 times higher than the undoped sample. The open-circuit potential of the synthetic films coupled with 403 stainless steel was shifted to more negative values and provided efficient photocathodic protection of stainless steel under light irradiation. In addition, the light absorption and photoelectrochemical behavior of chromium doped TiO 2 nanotube samples was improved under light irradiation in comparison with undoped TiO 2 nanotubes. • Chromium doped TiO 2 nanotube films were prepared by one-step anodization of titanium. • Chrome alum was used as a non-toxic chromium ion (Cr 3+ ) source. • The effects of various Cr 3+ concentrations on photocathodic protection behavior was studied. • The photocurrent density of chromium doped TiO 2 electrodes was enhanced up to 2.4 times compared to the undoped sample