A novel approach toward attachment of graphene oxide on copper using electrochemical grafting of an organic interlayer with enhanced corrosion performance

Abstract

This paper proposes a novel approach for attaching a graphene oxide (GO) film to a Cu substrate using diazonium chemistry. For this purpose, Cu was covalently modified using electrochemical grafting of p-phenylenebis(diazonium) salt (p-PBDS) followed by immersion in a basic GO suspension. The presence of the p-PBDS interlayer facilitated the assembling of GO in a multilayered film instead of a single layer as for the bare Cu substrate. The corrosion performance of the modified Cu was evaluated in 3.5% NaCl aqueous solution using potentiodynamic polarization and electrochemical impedance spectroscopy. The results inferred that the coupling of GO with p-PBDS interlayer protects effectively Cu against corrosion. Due to a low porosity percentage (0.003%), the corrosion current density is decreased by a factor of ∼ 5. It means that the coupling of GO multilayer with p-PBDS considerably prolongs the diffusion pathways for an oxidant toward the substrate. In this way, the polarization resistance of the film was increased by a factor of ∼ 4.5 (to 10.9 kΩ cm2) compared with that of a bare Cu substrate.