Estudio cuanto-mecánico de las propiedades electrónicas y estructurales de la interacción de Radón (222Rn) con grafeno.

Abstract

The main purpose of this study was to conduct a quantum-mechanical study of the electronic and structural properties of the interaction of radon (222Rn) with graphene.The calculations were based on the functional density theory (DFT), using the local density approximation (LDA), generalized gradient approximation (GGA) and a hybrid functional (vdW-GGA). The radon/ graphene interaction was analyzed in three conformational sites: C (center of a hexagon), T (on a carbon atom), and B (on a bond between carbon atoms). In order to take into account the topological defects, vacancies near to site C were chosen, and, to consider the low degree of oxidation, graphene oxide was used. Through the binding energy, it was determined that the most stable site for the adsorption of radon is in the C position, independently of the molecular structure considered. The results coming from the functional ones reported an energy of adsorption of 841.8 meV with LDA a distance of 3.56 angstrom, whereas with GGA the binding energy was of 722.5 meV, and a distance of 4.16 angstrom. Finally, considering the Van der Waals interaction, the bond energy reached is -584.7 meV at a distance of 3.9 angstrom. By creating topological defects, the obtained adsorption energy is -584.7 meV and a distance of 3.9 angstrom and e is graphene oxide, the binding energy is -539.0 meV and a distance of 3.81 angstrom. The spectrum of the density of state (DOS) of the interaction Radon / graphene, indicates that the cone of Dirac in graphene, is slightly affected and evidences two peaks at -17.5 eV and -3.5 eV, which are absent in the intrinsic graphene, concluding that there is adsorption of radon on graphene. It is advisable to carry out a study of band structure.