Enhanced adsorption of graphene oxide on iron surface induced by functional groups

Recent experiments have shown that graphene (Gr) and graphene oxide (GO) as coatings can be adsorbed on steel to effectively protect the surface. In this study, the density functional theory calculations have been carried out to investigate the effect of functional groups (hydroxyl and epoxy groups) on the adsorption of GO on iron surface. Our results show that the increased functional groups make the adsorption of GO on iron surface more favorable, which originates from the enhancement of localized C-Fe bonds around the functional groups. Within the maximum coverage of functional group on GO studied in this work, the maximum binding energy between GO (the ratio of oxygen to carbon is 0.09) and the Fe(1 1 0) surface is more than twice that of Gr/Fe model, suggesting that the introduction of functional groups on graphene basal plane can significantly improve the interaction strength of GO with the Fe substrate. This work provides an atomic-level insight into the adsorption mechanism of graphene-based materials on steel.