Structural Characteristics and Chemical Reactivity of Doped Graphene Nanosheets

We examine the structural properties and chemical reactivity of the graphene nanosheets (GNs), represented by circular CnHm-like cluster model with armchair edge, when doped with elements of the first row of the elements periodic table, such as: Be, B, N, B-N, O and F. We use the Density Functional Theory (DFT) based in the scheme developed by Perdew-Wang to represent the exchange-correlation functional, i.e., we perform a survey about local properties. According to our analysis we observed that only for situations when GNs contain two atoms of oxygen and fluorine there are not O-O and F-F bonds. In this case we observed how the honeycomb flat lattice is strained when it undergoes a C-C bond dissociation. On the other hand, we noted variations in the difference of HOMO-LUMO energy in doped GNs, whose values are: 1.04 (G: Be), 0.55 (G: B) 0.57 (G: N), 1.26 (G: O) and 2.19 eV for the G doped with fluorine. The polarity of these systems is kept with a low value (covalent characteristic) and only when they are doped with B and N the polarity is increased to 2.17 D. Furthermore, we observe that only the nitrogen and oxygen impurities increase the chemical reactivity of graphene; this analysis was performed in terms of the molecular electrostatic potential (MEP), in order to explore intermolecular properties such as the charge distribution.