Graphene nanoplatelets coating for corrosion protection of aluminum substrates

In this work, the properties of re-assembled graphene nanoplatelets were studied as an effective anticorrosion coating for aluminum (Al) substrate in 0.5 M sodium chloride (NaCl) solutions at room temperature (30°C). Scanning and transmission electron microscopy, as well as Raman spectroscopy, reveal the high-quality multilayer graphene nanoplatelets. The modifications of the corrosion resistance characteristic were investigated by open-circuit potential, followed by electrochemical tests such as potentiodynamic polarization (Tafel curves) and electrochemical impedance spectroscopy. The electrochemical results showed that the graphene nanoplatelets provided effective resistance against the corrosive medium during the two weeks of immersion in the saline medium. Scanning electron microscopy, Raman spectroscopy, and energy dispersive x-ray studies performed after immersion in the corrosive medium confirmed that a graphene-coated aluminum surface was well protected compared to an uncoated substrate.