Hydrogen dissociation in Li-decorated borophene and borophene hydride: An ab-initio study

Abstract

Lithium (Li) dopants have garnered attention as a means to enhance hydrogen (H2) binding energies and capacities in 2D boron-based materials. However, it is unclear if and how these dopants affect H2 dissociation and chemisorption. Using density functional theory (DFT) and nudged elastic band (NEB) calculations, reaction pathways for H2 dissociation on borophene-hydride and striped-borophene are investigated in the presence of Li dopants. Our results indicate that tuning the Li-loading can increase the reversibility and the rate of dehydrogenation for both borophene-hydride and striped borophene. In particular, for Li-doped borophene-hydride, the heat of reaction for H2 release is reduced by more than 85% compared to the pristine structure (1.97 eV/H2). Our results signify that Li-doping can considerably change the H2 chemisorption properties of striped-borophene and borophene-hydride, and can lead to promising materials for H2 storage.