Remarkable Hydrogen Storage Capacity In Li-Decorated Graphyne: Theoretical Predication

Abstract

On the basis of first-principles density functional calculations, we predict that Li-decorated graphyne can serve as a promising candidate for hydrogen storage, with a largest storage capacity of 18.6 wt %. The average adsorption energy of hydrogen is about −0.27 eV/H 2 , indicating that the doped system is an ideal hydrogen storage material at ambient conditions. It is proposed that the polarization mechanism, which stems from the electric field induced by the ionic Li coated on the graphyne, plays a key role in the adsorption of H 2 molecules. Furthermore, the formation of the hydrogen−hydrogen complex also stabilizes the adopted hydrogen molecules.

Symmetry-dependent transport properties and bipolar spin filtering in zigzagα-graphyne nanoribbons

“…Besides graphene, graphyne, a new allotrope of carbon containing sp and sp 2 hybridized carbon atoms, has also been the subject of interest [20][21][22][23][24][25][26][27][28][29][30] . Due to the presence of acetylenic bonds in the structure, graphyne is thought to have rich electronic and optical properties that are different from those of graphene 31 .…”

Communication: Oscillated band gaps of B/N-codoped α-graphyne

“…[7][8][9][10][11][12] One of the most attractive properties is how to control the linear band structure near the famous Dirac cones. 7,9,13,14 Graphyne is a new carbon-based form that consists of planar carbon sheets containing sp and sp 2 bonds, [15][16][17][18] which can be regarded as the big hexagonal rings joined together by the acetylenic linkages (C-C≡C-C) rather than the C-C=C-C in graphene. In experiment, although large graphyne structures have not been synthesized yet, graphdiyne (expanded graphynes) films and graphdiyne tubes have been already obtained.…”

A first-principles study of alkali-metal-decorated graphyne as oxygen-tolerant hydrogen storage media

“…Pristine and Li-or Ca-decorated graphyne are proposed as high capacity hydrogen storage media with moderate binding energies of molecular hydrogen. Interestingly, the storage capacity of pristine and Li-decorated graphyne exceeds 10 wt% according to recent studies [3]. Multi-layered-graphyne is predicted to have significantly larger specific and volumetric capacities than graphite, which is a promising factor for lithium storage as to replace graphite [4].…”

“…The existence of the Dirac cones was explained by the tightbinding calculations that map graphyne to graphene with effective hopping integrals [2]. In addition to its interesting electronic properties, graphyne is also intensively investigated as a storage medium of clean energy carriers like hydrogen or lithium due to its porous structure and high surface area [3][4][5][6][7][8]. Pristine and Li-or Ca-decorated graphyne are proposed as high capacity hydrogen storage media with moderate binding energies of molecular hydrogen.…”