CHAPTER 13: Principle, Properties, and Applications of Graphene and Graphene Oxide as Anticorrosion Coating Materials

Although graphene possesses excellent impermeability and chemical inertness to oxidizing gases or corrosive solutions, its high electrical conductivity, discontinuity, presence of defective sites, and lack of surface functional moieties have restricted its application range as anticorrosion coating material. A typical example is that graphene films grown by chemical vapor deposition on copper and other metals as ultrathin coatings are not able to provide long-term corrosion protection for the underlying metals, since the excellent conductivity of the graphene film, along with the existence of defects, greatly promote the galvanic corrosion of said underlying metals. At present, graphene, graphene oxide (GO), and reduced graphene oxide (r-GO) are mainly used as nanofiller additives in anticorrosion coatings or as interlayers in layer-by-layer self-assembled multilayer films by extending the diffusion pathways of corrosive electrolyte ions to the surface of the coated metal substrate. In this sense, the functionalization of graphene and GO is not only necessary but also urgent. It is possible that the application range of graphene-based carbon materials can be broadened to a considerable extent by means of surface functionalization.