Role of oxygen functionalities of GO in corrosion protection of metallic Fe

We demonstrated the mechanism that makes Graphene Oxide (GO) a superior material for corrosion protection over reduced graphene oxide (rGO) and nitrogen doped reduced graphene oxide (N-rGO). According to the results of our electrochemical study, supported by a host of characterization methods and density functional theory (DFT) based calculations, reduction of GO to synthesize rGO or doping of foreign heteroatoms like nitrogen to synthesize N-rGO, exposes and/or creates the defects/pores on the basal carbon plane of GO. Through these defects/pores of rGO and N-rGO, the corrodants react with the metal-surface and corrode it. A subnanometric layer of GO adhered to carbonyl iron (CI) surface through grafting by a thin Glycine (Gly) layer, repels the corrodants and shows robust corrosion protection performance in 1 M KCl solution, over a similar layer of rGO or N-rGO. Hence, our work demonstrate that a coating of GO on metallic Fe surface, grafted via a thin glycine layer, is the economical solution and has the robust performance for its direct industrial application for corrosion protection. (C) 2020 Elsevier Ltd. All rights reserved.

Automated summary

The study demonstrates that graphene oxide (GO) grafted with a glycine layer provides more reliable corrosion protection for metals compared to reduced graphene oxide (rGO) and nitrogen-doped reduced graphene oxide (N-rGO).