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Main Authors: Jaiswal, Ankita, Sahoo, Rakesh K., Sahu, Sridhar
Format: Preprint
Published: 2024
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Online Access:https://arxiv.org/abs/2407.16420
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author Jaiswal, Ankita
Sahoo, Rakesh K.
Sahu, Sridhar
author_facet Jaiswal, Ankita
Sahoo, Rakesh K.
Sahu, Sridhar
contents This article presents the reversible hydrogen storage capacities of Li-decorated Si6C14 and Si8C12 using Density Functional Theory (DFT). The chemical stabilities of the designed Si6C14Li6 and Si8C12Li4 nanocages are investigated using HOMO-LUMO gaps and various global reactivity descriptors such as chemical hardness and electrophilicity index. Our study reveals that each Li atom decorated over the designed Si6C14 and Si8C12 nanocages can hold up to 5H2 molecules with adsorption energy lying in the optimum range of 0.14-0.085 eV, thereby yielding an overall gravimetric density of 13.8% and 9.2% respectively. The interaction between adsorbed H2 molecules and the Li metal sites is found to occur via non-covalent and closed shell type of interaction. The H2 molecules are adsorbed in a quasi-molecular fashion with elongated bond length. The molecular dynamics study reveals that most of the H2 molecules get desorbed from the designed host nanocages at 300K without causing any significant structural changes, which confirms their reversibility. When the adsorption and desorption conditions are set at 100K/60bar and 240K/1bar respectively, the practical storage gravimetric densities of Si6C14Li6 and Si8C12Li4 cages are estimated to be 13.73 wt% and 9.08 wt%, which are relatively high in comparison to the US-DOE target of 5.5 wt% by the year 2020. Hence, the computationally designed Si6C14Li6 and Si8C12Li4 nanocages can be regarded as prospective systems for hydrogen storage applications.
format Preprint
id arxiv_https___arxiv_org_abs_2407_16420
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Feasibility of Li decorated Si6C14 and Si8C12 nanocages as promising hydrogen storage media: A computational study
Jaiswal, Ankita
Sahoo, Rakesh K.
Sahu, Sridhar
Materials Science
Applied Physics
This article presents the reversible hydrogen storage capacities of Li-decorated Si6C14 and Si8C12 using Density Functional Theory (DFT). The chemical stabilities of the designed Si6C14Li6 and Si8C12Li4 nanocages are investigated using HOMO-LUMO gaps and various global reactivity descriptors such as chemical hardness and electrophilicity index. Our study reveals that each Li atom decorated over the designed Si6C14 and Si8C12 nanocages can hold up to 5H2 molecules with adsorption energy lying in the optimum range of 0.14-0.085 eV, thereby yielding an overall gravimetric density of 13.8% and 9.2% respectively. The interaction between adsorbed H2 molecules and the Li metal sites is found to occur via non-covalent and closed shell type of interaction. The H2 molecules are adsorbed in a quasi-molecular fashion with elongated bond length. The molecular dynamics study reveals that most of the H2 molecules get desorbed from the designed host nanocages at 300K without causing any significant structural changes, which confirms their reversibility. When the adsorption and desorption conditions are set at 100K/60bar and 240K/1bar respectively, the practical storage gravimetric densities of Si6C14Li6 and Si8C12Li4 cages are estimated to be 13.73 wt% and 9.08 wt%, which are relatively high in comparison to the US-DOE target of 5.5 wt% by the year 2020. Hence, the computationally designed Si6C14Li6 and Si8C12Li4 nanocages can be regarded as prospective systems for hydrogen storage applications.
title Feasibility of Li decorated Si6C14 and Si8C12 nanocages as promising hydrogen storage media: A computational study
topic Materials Science
Applied Physics
url https://arxiv.org/abs/2407.16420