LAUSR

Abstract Nanocrystalline Zn–Ni alloy is easily to be oxidized after exposed in the air, and the formed locally oxidized film can provide an additionally novel photocathodic protection to the bare grain surface under sunlight illumination in simulated seawater. A much lower corrosion rate of nearly 30% is obtained for locally oxidized nanocrystalline Zn–Ni alloy under sunlight condition compared to the dark condition. The anticorrosion mechanism is achieved by cooperating following two mechanisms: photocathodic protection of photoelectrons on the reaction of zinc oxidation, and shielding effect of the formed new zinc based precipitation under sunlight illumination. This is a simple and economical approach with the promise for large-scale application in enhancing corrosion resistance of Zn–Ni alloys.