Corrosion Science and Mitigation Strategies: Role of Graphene and Nickel-Graphene Composite Coatings in Next-Generation Protection

Corrosion is a naturally occurring electrochemical degradation process that imposes severe economic and safety burdens on modern society by reducing the service life of metallic infrastructures in transportation, marine systems, electronics, and energy industries. From a fundamental standpoint, corrosion represents a spontaneous chemical reaction governed by thermodynamic feasibility and electrochemical kinetics, where the driving force is often explained through the Second Law of Thermodynamics and the relative stability of oxidation states in aqueous environments. Accordingly, standard reduction potentials provide an effective framework for predicting the tendency of metallic dissolution and cathodic reduction reactions under practical conditions. This review summarizes the fundamental principles of corrosion, including major corrosion forms such as uniform corrosion, galvanic corrosion, pitting, crevice corrosion, intergranular corrosion, and stress corrosion cracking. A critical discussion is presented on conventional corrosion mitigation strategies, including inhibitors, cathodic protection, alloying, surface passivation, and protective coatings. Particular emphasis is placed on graphene as an emerging corrosion-resistant material due to its high chemical stability, mechanical strength, and exceptional impermeability to aggressive species. The role of graphene as a diffusion barrier is analyzed in terms of defect density, interfacial adhesion, and microstructural integrity. Furthermore, recent progress in nickel–graphene composite coatings is reviewed, highlighting their improved barrier properties, grain refinement effects, enhanced polarization resistance, and suppression of localized corrosion processes. Finally, current challenges and future research directions are outlined, focusing on scalable fabrication, dispersion stability, long-term durability, and the development of multifunctional graphene-enabled anticorrosion coatings for industrial deployment.