Hydrogen adsorption on Li decorated graphyne-like carbon nanosheet: A density functional theory study. (21st September 2020)

• Record Type: Journal Article
• Authors: Liu, Yang; Gao, Shuxi; Lu, Fang; Yu, An; Song, Senchuan; Shi, Huahong; Mai, Yuliang; Liao, Bing
• Is Part Of: International journal of hydrogen energy. Volume 45:Number 46(2020)
• Page Start: 24938
• Page End: 24946
• Publication Date: 2020-09-21
• Subjects: Hydrogen adsorption -- Graphyne-like carbon nanosheet -- Density functional theory -- Li-decoration; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2020.06.072
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: 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 C68 -GY, 14H2 molecules were captured. The maximum hydrogen storage density was 8.04 wt% with an average hydrogen adsorption energy of −0.227 eV per H2 . The positively charged Li atoms aroused electrostatic field and induced the polarization of H2 . It was notable to observe strong hybridization between the main peak of H-1 s orbitals with Li below Fermi level, which was responsible for the enhancement of hydrogen binding energy, indicating its potential application on hydrogen storage. Highlights: Hydrogen storage density is 8.04 wt% with adsorption energy of −0.227 eV. Both DFT and AIMD calculations show Li would be dispersed separately. Hydrogen binds with Li/C through polarization and H–H interaction among molecules. The hybridization of H and Li makes major contribution to enhance binding energy.