Avoiding oxidation with coating: graphene protected magnesium surfaces

Magnesium is a promising material for the automotive technology. Avoiding its spontaneous oxidation is, however, mandatory for a feasible industrial application of this metal. We perform computer simulations to demonstrate that a protective graphene layer can successfully avoid the oxidation of a magnesium material. This feature remains true even when the graphene layer has several simple defects, such as vacancies and Stone-Wales transformations. In fact, the defects actually increase the strength of the graphene/metal interaction, further enhancing the protective properties. These results are rationalized in terms of the low Mg cohesive energy, that allows the system to quickly reconstruct and adapt.