Insights into the influence of functional groups on the properties of graphene from first‐principles calculations

Abstract

Carbon dots (CDs) are a kind of popular carbon nanomaterials with many functional groups that can be used in catalysis. However, in terms of calculation and simulation, most researchers choose to simplify CDs to pure graphene (GR) or graphene doped with nitrogen, boron, oxygen, and other elements due to the complexity of the calculation. In this study, the effects of adsorption of some functional groups (carboxyl, amino, and hydroxyl) on the properties of graphene have been investigated through first-principles calculations. The calculated results suggest that the adsorbed carboxyl group on graphene is relatively unstable, while the amino and hydroxyl groups can form covalent bonds with carbon atoms on the graphene and capture some electrons. When the bifunctional groups are adsorbed on the para or ortho position, it is beneficial for enhancing their stability on the graphene. However, when the bi-functional groups are adsorbed on the meta position, it will reduce the stability of the functionalized graphene. This research is beneficial for evaluating the specific functional groups on the surface of CDs, and it has particular significance for the simulation and modeling of CDs.

Epoxy Coatings Containing Modified Graphene for Electromagnetic Shielding

“…Considering the first modification approach, small molecules or functional groups, the introduction of new functionality on the graphene backbone results in a decrease of thermal stability. Both HMDA and PB afforded similar results with a residual mass of over 65% at 900 • C. As expected, the oxidation of graphene resulted in the introduction of functional groups hydroxyl [34,35], carboxyl [34,36,37], and oxirane [38], but the registered weight loss is lower than that afforded by the graphene functionalized by the radical grafting of benzoyl peroxide radicals and HMDA addition. The TGA results for polymer functionalized graphene indicate a relatively low polymer to graphene ratio in the case of methyl methacrylate and hexyl methacrylate.…”