Passivation of microbial corrosion using a graphene coating

Microbial corrosion limits the use of metallic structures in a variety of technological processes and applications. Here, we report the first demonstration of graphene as a passive layer that retards microbially-induced galvanic corrosion (MIC) of metals for extended periods of time (∼2700 h). The effectiveness of the MIC-resistant graphene coating was evaluated under realistic operating conditions by testing baseline Ni foams and graphene-coated Ni foams as anodes in a microbial fuel cell. The rates of Ni dissolution in the graphene-coated Ni anode were at least an order of magnitude lower than the baseline (uncoated) Ni electrode. Electrochemical impedance spectroscopy characterization revealed that the MIC of Ni was impeded by over 40-fold when coated with graphene.