New capability of graphene as hydrogen storage by Si and/or Ge doping: Density functional theory

摘要

We studied the adsorption of water molecules via the density functional theory on the pure and silicon and/or germanium doped graphene. We investigated the electrostatic surface potential of the structures to predict the possible interactions. Also, we examined the interaction between every possible side of the water molecule and possible sites of the pure and doped graphene. There was no interaction between the water molecule and the graphene. The only interaction was between the oxygen atom of the water molecule and the doped atoms. We also studied the decomposition of the water molecule on these doped graphene sheets and the possible intermediates and transition states and reaction pathway for the decomposition process. We calculated the interaction energies for the adsorption steps and the thermodynamic parameters for all steps of reaction pathway. The results showed that the adsorption of the water molecule on silicon and/or germanium doped graphene. Also, the decomposition of one of the hydrogen atoms of water molecule was thermodynamically favored at room temperature. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.