A novel lithium decorated N-doped 4,6,8-biphenylene for reversible hydrogen storage: Insights from density functional theory

Two-dimensional (2D) carbon-based (C-based) and carbon-nitrogen (C-N) materials have great potential in the energy harvest and storage fields. We investigate a novel carbon biphenylene (C468) consisting of four-, six- and eight-membered rings of sp2 carbon atoms (Fan et al., Science, 372:852-6 (2021)) for hydrogen storage. Using first-principles based Density functional theory calculations, we study the geometrical and electronic properties of C468 and N-doped C468. Lithium (Li) atoms were symmetrically adsorbed on both sides of the substrate, and their adsorption positions were determined. The maximum gravimetric density of hydrogen (H-2) adsorbed symmetrically on both sides of Li atom was studied within the scope of physical adsorption process (-0.2 eV/H-2 similar to -0.6 eV/H-2). Lidecorated C468 can adsorb 8 upper hydrogen molecules and 8 lower hydrogen molecules, and Li-decorated N-doped C468 can adsorb 9 upper hydrogen molecules and 9 lower hydrogen molecules. The gravimetric densities of Li-decorated C468 and Li-decorated Ndoped C468 can reach 9.581 wt% and 10.588 wt%, respectively. Our findings suggest significant insights for using Li-decorated C468 and Li-decorated N-doped C468 as hydrogen storage candidates and effectively expand the application scope of C-based materials and C-N materials. (c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

We investigate a novel carbon biphenylene (C468) and its nitrogen-doped counterpart as potential candidates for hydrogen storage. The findings show that lithium-decorated C468 and lithium-decorated N-doped C468 can adsorb a considerable amount of hydrogen molecules, with gravimetric densities reaching 9.581 wt% and 10.588 wt%, respectively. These results provide significant insights for expanding the application scope of carbon-based and carbon-nitrogen materials and advancing hydrogen storage technologies.