Improved corrosion resistance of copper coated by graphene

High quality graphene on a Cu foil was synthesized by atmospheric pressure chemical vapor deposition. The morphology and microstructure of specimens were characterized by optical microscopy, scanning electron microscopy, high-resolution transmission electron microscopy, Raman spectroscopy, ultraviolet-visible spectroscopy and X-ray photoelectron spectroscopy. The corrosion resistance of specimens was tested by potentiodynamic polarization and electrochemical impedance spectroscopy. Results show that monolayer and high quality tri-layer graphene are synthesized at 1000 degrees C for 5 and 15 min depositions, respectively. The monolayer graphene cannot protect Cu efficiently from oxidation at 300 degrees C in air and from electrochemical corrosion in a 0. 1 M NaCl solution due to its abundant defects and grain boundaries. The tri-layer graphene effectively increases the oxidation resistance and the electrochemical corrosion resistance. The protective performance of tri-layer graphene for a Cu foil is significantly better than that of monolayer graphene.