Elevating the photo-generated cathodic protection of corrosion product layers on electrogalvanized steel through nano-electrodeposition

•The photo-electrochemical property of Zn’s corrosion products is demonstrated.•The ZnO layer provides about 30% of photo-generated cathode protection for Zn.•Nano-electrodeposition further elevates its protection efficiency to about 100%.•Because nano-Zn accelerates the reaction kinetics of the formation of ZnO layer.