An exploration on anti-corrosion performance of electrochemically synthesized graphene coating on commercially pure copper

Abstract

Graphene, a path-breaking discovery of the last decade has opened up numerous research avenues with its superior properties. The present work focuses on electrochemical exfoliation of graphite in sodium sulphate (Na2SO4) aqueous solution of 4 different molar concentrations to synthesize graphene. XRD and EDS analysis substantiate the presence of graphene platelets along with traces of oxygen. Raman studies pointed out that the graphene synthesized at lower molar concentration had less defects owing to slow and smooth exfoliation. UV studies point out to electronic transitions in CC bonds present in the graphene sheets. Graphene with few layered structures and stacked onto one another, were obtained for all concentrations as confirmed through SEM studies. Transparent, curled layers are depicted through TEM analysis. FTIR study confirms presence of functional groups, which is minimum at lower molarities of exfoliating solutions. Then after, graphene platelets were coated onto copper substrates by electrophoretic deposition at a constant voltage of 5 V. The coated samples are then made to undergo corrosion tests in 3.5 wt% NaCl solution. Graphene coatings prove effective in combating corrosion and it is worth noting that bi-layer coatings prove to be more efficient in comparison to single or multi-layer coatings.