Electrodeposited Nickel Coating Reinforced with Chlorophyll-Reduced Graphene Oxide

Nickel composite coating reinforced with reduced graphene oxide is fabricated by pulse electrodeposition method from a surfactant-free bath at different current densities. The reduction of graphene oxide is done by an ecofriendly method which uses chlorophyll (CHL) as the reducing agent. The CHL also acts as a stabilizer because of its amphiphilicity. Auger electron spectroscopy is used to study the surface morphology and characteristics of the deposited coatings. Nanoindentation is used to study the mechanical properties. Electrochemical techniques such as potentiodynamic polarization and electrochemical impedance spectroscopy are used to study the corrosion behavior in 3.5 wt% NaCl solution. The coatings are found to exhibit superior hardness, Young's modulus, and corrosion resistance when compared with the pure Ni coating. Hardness and corrosion resistance are found to improve almost tenfold at optimized condition. Scanning electron microscopy of the corroded surface of the coatings provides an insight into the corrosion process.