Graphene nanosheets for enhancing the corrosion resistance of stainless steel in marine environments

This study presents a sustainable and cost-effective approach for enhancing the corrosion resistance of stainless-steel (SS) using graphene nanosheet (GNSs) coatings. GNSs were produced via liquid-phase shear exfoliation in water and deposited onto SS through an interfacial self-assembly process to form uniform and well-adhered films. Structural and morphological characterization confirmed the formation of highly crystalline few-layer graphene (3 to 5 layers) with lateral sizes of 50–80 nm. Continuous coatings with thicknesses ranging from 30 to 120 nm were obtained by varying the number of deposition cycles. Electrochemical measurements demonstrated that the self-assembled graphene coating significantly improved corrosion protection. Compared with bare SS, coated samples exhibited a more noble E_corr (− 30 mV), a fivefold reduction in Jcorr (12 nA.cm⁻²), nearly double the polarization resistance (Rp = 253 kΩ), and an almost fourfold decrease in corrosion rate. EIS measurements further confirmed the long-term protective performance of the coating. Post-immersion SEM, Raman, and XRD analyses revealed excellent structural stability in a marine environment, with no detectable corrosion products. These findings demonstrate that self-assembled graphene nanosheet films act as effective barriers against chloride-induced corrosion, highlighting their potential as durable, ultrathin and environmentally friendly protective coatings for metallic substrates.