Synthesizing a novel fluorinated reduced graphene oxide-CeO2 hybrid nanofiller to achieve highly corrosion protection for waterborne epoxy coatings

Abstract

Although fluorinated graphene (FG) inherits the physical barrier characteristic from graphene, its limited dispersibility seriously impedes its application in corrosion resistance. Here, this study aims to present a facile strategy to effectively eliminate this undesired feature of FG. We developed a well-dispersed cerium oxide grafting fluorinated reduced graphene oxide (FrGO@CeO2) nanofiller to enhance the anti-corrosion properties of epoxy coating on Q235 mild steel surfaces. The in situ F-doping and hydrothermal techniques were employed to synthesize FrGO@CeO2 nanofillers and functionalize them with waterborne epoxy coating. Combining the electrochemical results and the corrosion morphologies, the resultant nanofillers were found to significantly reinforce the protection properties of epoxy coatings due to the physical barrier effect derived from FrGO. In addition to impermeability, FrGO presented the insulating nature and endowed composite coatings to combat galvanic corrosion. Local electrochemical impedance spectroscopy (LEIS) indicated that cerium oxide adsorbed on mild steel surface could form a passive layer and thus further resisted the metal corrosion process. The related corrosion protection mechanism of FrGO@CeO2/EP coating was proposed in detail, which could provide broader platforms for designing new corrosion protection materials.