Copper-graphene oxide composite coatings for corrosion protection of mild steel in 3.5% NaCl

This paper investigates the effect of graphene oxide (GO) on morphology, microstructure and corrosion behaviour of Cu-GO composite coatings. Cu-GO composite coatings were electrodeposited on mild steel substrate by dispersing chemically synthesised GO into a Cu electrolytic bath. Anionic surfactant (sodium lauryl sulphate) was used to obtain uniform and compact coating morphology. Incorporation of GO into Cu matrix produced a finer granular coating morphology with a strong 〈220〉 preferred orientation. The analysis of electrochemcial corrosion test results revealed that steels coated with Cu-GO were invariably more corrosion resistant compared to both bare steel and pure Cu coated steel. Extent of the reduction in the corrosion rate increased with increasing amount of GO in electrodeposited Cu matrix. Improved corrosion resistance of Cu-GO coatings was related to 〈220〉 texture and high impermeability of GO to Cu⁺ ions and dissolved O₂ in the chloride media.