Exploring the Impact of Electric Field and OLi 3 Decoration on Inorganic Graphenylene SiC for Reversible Hydrogen Storage: A First-Principles Investigation

High Resolution Image Download MS PowerPoint Slide The hydrogen storage capacity of superalkali OLi 3 -decorated inorganic graphenylene SiC (IGP-SiC) has been explored using first-principles calculations employing the GGA-PBE functional. Notably, OLi 3 is found to be strongly bonded to the IGP-SiC monolayer with a binding energy of −3.89 eV. Thus, a positive charge is developed on the lithium atom of OLi 3 due to charge redistribution, which enhances its hydrogen adsorption energy. The interaction of H 2 with OLi 3 @IGP-SiC involves charge polarization as well as orbital and van der Waals interactions. Our calculations reveal a remarkable hydrogen storage capacity of 10.93 wt %, surpassing the DOE-recommended limit of 6.5 wt %, where the hydrogen adsorption energy is found to be in the range of −0.19 to −0.15 eV/H 2 . To assess the thermal stability and reversibility of hydrogen storage exhibited by OLi 3 @IGP-SiC, ab initio molecular dynamics (AIMD) simulations were performed at temperatures of 100, 200, and 300 K. Hydrogen adsorption energy ( E H 2 ad ) of OLi 3 @IGP-SiC can be tuned by applying an electric field. It is noticed that E H 2 ad in OLi 3 @IGP-SiC + 1H 2 is increased from −0.197 eV/H 2 (at zero electric field) to −0.657 eV/H 2 upon application of a +0.055 V/Å electric field. Furthermore, by employing the climbing-image nudged elastic band method, the hydrogen diffusion energy barrier is found to be 0.054 eV. Therefore, the OLi 3 -decorated IGP-SiC monolayer designed in this study may serve as a potential reversible hydrogen storage material.