Solar energy protects steels against corrosion: Enhanced protection capability achieved by NiFeO decorated BiVO4 photoanode

Abstract Coupling n -type semiconductor photoelectrode with steels provides protection from corrosion for the latter by pumping electrons produced by water oxidation reaction in a sustainable way. Although the concept of the photocathodic protection of steels has been proposed for about two decades, this technique is still far away from practical applications due to the limited protection capability. In this work, we reported that the BiVO 4 photoanode significantly decreases the self-corrosion potential of 316 steel by 166 mV, and the decoration of NiFeOx films onto BiVO4 further shifts the self-corrosion potential by ∼90 mV negatively, which exhibits an excellent protection capability. The protection capability of the photoelectrode to steel is limited by the relative position of the Fermi level of the semiconducting material , and confined by the thermodynamics of the surface reactions on the semiconductor-electrolyte interface.