▎ 摘　　要

The detailed mechanisms of graphene to protect magnesium and its alloys are of paramount importance owing to their vulnerable oxidizing corrosion disadvantage. Herein, a density functional theory is used to comprehensively reveal the specific adsorption and penetrating diffusion processes of O adatom on the non-, F-, N-, B-, Si-, P-, S-doped defective graphene, respectively. Theoretical simulations confirm that the graphene is an effective protector for the vulnerable oxidizing corrosion surface of magnesium and its alloy, but the chloride gives rise to the penetrating diffusion of oxygen to be much easier through the defective graphene, which significantly deteriorates its protecting ability to the magnesium surface. Fortunately, we find that the optimal B-doped defective graphene with the highest penetrating diffusion energy barriers can provide a reliable ability to effectively protect vulnerable oxidizing magnesium surface, and thus it can achieve superior oxidative and corrosive resistances in the marine.