Greatly Enhanced Anticorrosion of Cu by Commensurate Graphene Coating

Abstract

Metal corrosion is a long-lasting problem in history and ultrahigh anticorrosion is one ultimate pursuit in the metal-related industry. Graphene, in principle, can be a revolutionary material for anticorrosion due to its excellent impermeability to any molecule or ion (except for protons). However, in real applications, it is found that the metallic graphene forms an electrochemical circuit with the protected metals to accelerate the corrosion once the corrosive fluids leaks into the interface. Therefore, whether graphene can be used as an excellent anticorrosion material is under intense debate now. Here, graphene-coated Cu is employed to investigate the facet-dependent anticorrosion of metals. It is demonstrated that as-grown graphene can protect Cu(111) surface from oxidation in humid air lasting for more than 2.5 years, in sharp contrast with the accelerated oxidation of graphene-coated Cu(100) surface. Further atomic-scale characterization and ab initio calculations reveal that the strong interfacial coupling of the commensurate graphene/Cu(111) prevents H₂O diffusion into the graphene/Cu(111) interface, but the one-dimensional wrinkles formed in the incommensurate graphene on Cu(100) can facilitate the H₂O diffusion at the interface. This study resolves the contradiction on the anticorrosion capacity of graphene and opens a new opportunity for ultrahigh metal anticorrosion through commensurate graphene coating.

Ultrahigh anticorrosion of Cu surfaces by commensurate graphene coating is demonstrated, which prevents both vertical and in-plane penetration of corrosive fluids. The large-scale application of graphene coating on metal surfaces as a long-term anticorrosion technique is therefore very promising in the near future.

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