Influence of the anion specificity on the anodic polarization of titanium

The anodic polarization of titanium in the presence of selected electrolytes at 0.1 mol/L concentration has been investigated. The results were interpreted according to the categorization of anions based on their cosmotrope/chaotrope character. The aggressiveness of the anions is found to be related for a part to their proneness to loose their hydration shell during the penetration of the passive film, provided they can access sufficiently to the passive surface.

Research highlights
► Anodic polarization of titanium in the presence of selected anions.
► Anion aggressiveness depends on their ability to dehydrate during penetration of the passive film.
► The cosmotrope/chaotrope categorization helps to rationalize the influence of ion nature in electrochemical corrosion of passive substrates.