Oxygen vacancy modified α-Fe2O3 nanorods provide an environment-friendly and efficient anti-corrosion passive film into polymer coating

Oxygen vacancy modified Fe2O3 (OV-Fe2O3) nanorods were fabricated and then used as epoxy coating fillers. The OV-Fe2O3 fillers passivates the steel substrate, because oxygen atoms can be stored in the vacancies to form a metastable state. Electrochemical impedance spectroscopy showed the impedance modulus of OV-Fe2O3 coatings was about 105 times higher than general α-Fe2O3 coatings after O2-high pressure and high-temperature corrosion. X-ray photoelectron spectroscopy and scanning vibrating electrode technique confirm OV-Fe2O3 can continuously transport oxygen from the oxygen-rich environment to the substrate surface (oxygen-deficient environment) before the permeation of the corrosive medium, eventually achieving efficient passivation.