Ab initio study of the effect of hydrogen adsorption on the electronic, magnetic and optical behavior of M-graphene (M = O, F) sheet

Abstract

Adsorption of hydrogen atoms on pure and modified graphene layers was studied by density functional theory (DFT). Modifications were made to the graphene layers by adding M adatom (M [Formula: see text] O or F). The relaxed structures, energetic, electronic and magnetic properties of the M-graphene, H-graphene and M-graphene-NH layers were studied theoretically using the full-potential linearized augmented plane wave (FP-LAPW) within the generalized gradient approximation (GGA). The results showed that the presence of O or F as adatom on graphene allowed the stability of multi-H atom adsorption with a large and positive adsorption energy. A bandgap opening was observed for O-graphene-3H and O-graphene-4H sheets. Also, O-graphene, O-graphene-H and F-graphene-NH were found to have metallic behavior. O-graphene-3H sheet was found to have a half-metallic ferromagnetic behavior since its total magnetic moments is equal to an integer. In addition, the band structure shows that O-graphene-3H sheet is a semiconductor. Useful optical applications are predicted for M-graphene-NH sheet due to the absorption and reflectivity results.