Effect of ZnO as corrosion product on corrosion behavior of zinc-iron corrosion protection systems

ZnO is a common corrosion product of Zn that may affect the corrosion behavior of Zn/CS in zinc-iron corrosion protection systems. This work is to elucidate the microscopic mechanisms underlying the corrosion promoting effects of ZnO on Zn /CS based on density functional theory. The charge conduction behavior between ZnO and metal contact interface is described. Namely, electrons can be continuously gained, rapidly consumed and conducted to support the cathodic reaction during corrosion, due to the oxygen reduction reactivity of ZnO. The results are conducive to enriching the theory of Zn used as sacrificial anode for corrosion protection.