Hydrogen adsorption on Li decorated graphyne-like carbon nanosheet: A density functional theory study

Motivated by novel graphyne-like carbon nanostructure C68-GY, spin-polarized DFT calculations with dispersion-correction were performed to investigate the hydrogen adsorption capacity of Li decorated C68-GY nanosheet. The binding energy between Li and C68-GY was larger than the cohesive energy of bulk metal, indicating Li atoms would prefer to separately attached on C68-GY. The ab initio molecular dynamics simulation has been performed to confirm the stability of Li/C complex. When five Li atoms decorated on C68GY, 14H(2) molecules were captured. The maximum hydrogen storage density was 8.04 wt% with an average hydrogen adsorption energy of -0.227 eV per H-2. The positively charged Li atoms aroused electrostatic field and induced the polarization of H-2. It was notable to observe strong hybridization between the main peak of H-1s orbitals with Li below Fermi level, which was responsible for the enhancement of hydrogen binding energy, indicating its potential application on hydrogen storage. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.