Migration of ions on oxygen-deficient chromium oxide electrodeposited from trivalent chromium electrolyte

The migration of cations on electrodeposited chromium surfaces, with and without a polymer coating, is studied by in situ scanning Kelvin probe measurements in an inert atmosphere. The reactivity of the chromium-based coating to the ambient atmosphere is studied using in operando ambient pressure X-ray photoelectron spectroscopy in different atmospheres and is shown to have significant impact on cation migration. These findings provide novel and deep insights into ionic mobility at surfaces and along interfaces. Furthermore, an improvement to the conventional cathodic delamination mechanism is proposed based on the outcomes of this study. [Display omitted] •Oxygen adsorbs reversibly on the oxygen-deficient chromium oxide electrodeposited from trivalent chromium electrolyte.•The resulting negative charge on the surface enhances cation transport in the presence of oxygen.•Changes in adsorbed species – associated with the change in atmosphere – influence cation migration.•Incorporation of cations into intact metal/polymer interface – possible rate-determining step during cathodic delamination.