Molecular modeling analyses for the effect of alkali metal oxides on graphene

Abstract

© 2018 by the authors. Alkali metal oxides such as CaO, MgO and SrO interacted with graphene. CaO was interacted with graphene through O then through Ca atoms. Graphene is supposed to interact with 1 CaO; 2 CaO; 3 CaO and 4 CaO molecules attached to its corner atoms. Additionally, CaO interacted with graphene through the middle atom of graphene through O of CaO. Each structure is supposed to interact with H2S, then two important physical quantities were calculated, namely total dipole moment and HOMO/LUMO band gap energy at B3LYP/3-21g* level of theory. Results indicated that the total dipole moment of modified graphene is increased while its HOMO/LUMO band gap energy is decreased. This enhances the ability for modified graphene to interact with H2S. The lowest bandgap energy (0.1703 eV) was corresponding to 2 MgO/graphene, while the highest total dipole moment (68.6390 Debye) was corresponding to 2 SrO/graphene-H2S. Results indicated the suitability of modified graphene to act as a sensor for H2S.