A DFT study on enhanced adsorption of H2 on Be-decorated porous graphene nanosheet and the effects of applied electrical fields

The adsorption of the hydrogen molecule on the pure porous graphene nanosheet (P-G) or the one decorated with Be atom (Be-G) was investigated by the first-principle DFT calculations. The Be atom was adsorbed on the P-G with a binding energy of -1.287 eV to successfully establish the reasonable Be-G. The P-G was a poor substrate to interact weakly with the H-2, whereas the Be-G showed a high affinity to the adsorbed H-2 with an enhanced adsorption energy and transferred electrons of -0.741 eV and 0.11 e, respectively. A molecular dynamics simulation showed that the H-2 could also be adsorbed on the Be-G at room temperature with a reasonable adsorption energy of -0.707 eV. The interaction between the adsorbed H-2 and the Be-G was further enhanced with the external electrical fields. The applied electrical field of -0.4 V/angstrom was found to be the most effective to enhance the adsorption of H-2 on the Be-G with the modified adsorption energy and the improved transferred electrons being -0.708 eV and 0.17 e, respectively. Our study shows that the Be-G is a promising substrate to interact strongly with the H-2 and could be applied as a high-performance hydrogen gas sensor, especially under the external electrical field. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.