Graphene oxide integrated into protective coatings against corrosion for metals and its alloys: A review

This review aims to discuss the effect of graphene oxide (GO) derivatives incorporated protective coatings on various metals against corrosion process in alkaline environments. These coatings increased hydrophobic character and adhesion strength between the coating and metal surface. Electrochemical measurements were used more often among all other techniques to investigate the effect of inhibitor in the polymer matrix (epoxy/silane sol). In some cases, the highest inhibition efficiency was achieved by electrochemically coating GO derivatives on the metal surface. GO derivatives prepared via the adsorption of Pr³⁺, Ce³⁺, and Zn²⁺ ions have revealed a good inhibition tendency for metals in acidic solution because of the exchange of Pr³⁺, Ce³⁺, and Zn²⁺ with those ions (Na⁺, Cl^–) in the corrosion electrolyte. Further, because of the adsorption of polar groups on GO onto the surface of metals, the hydrophobicity achieved by modified GO coating limits the infiltration of corrosive ions and enhances inhibitory efficiency. And, scratches were foreseen during the manufacturing of coatings on metallic substrates, and this harms the organic coatings. The defect created by impurities developed coatings deterioration that was prone to the diffusion of corrosive substances, severely reducing the coatings’ lifespan. Grafting graphene oxide with various functional groups was used to achieve self-healing behavior in organic coatings. At the defective site of the metallic substrates, self-healing by functionalized graphene oxide created dense protective coatings.