Adsorption and decomposition of water molecules on Al and/or Ga-doped Graphene at ambient temperature: density functional theory

Abstract

To use H2 gas as a common fuel it needs to be in high pressures or cryogenic temperatures to have reasonable density. But, if we have adsorbent materials with high volumetric capacities to store hydrogen at ambient temperature and low pressure without any compressing it is worthwhile to use hydrogen as clean and reversible fuel. Here, we want to report the adsorption and decomposition properties of aluminum and gallium-doped graphene at ambient temperature. We studied the adsorption of H2O molecule on pure and doped graphene via density functional theory. So, possible interactions between the H2O molecule from three sides and pure and aluminum and gallium-doped were examined. After adsorption, decomposition of the H2O molecule has been studied and so on, for receive a reaction pathway, possible intermediates and transition states has been studied. To continue the density of states, interaction energies and thermodynamic parameters have been calculated. The results showed that the adsorbed water on aluminum and/or gallium-doped graphene decompose to OH and H and then adsorb on the surface again at ambient temperature and this process was thermodynamically favorable.