Lithium clusters on graphene surface and their ability to adsorb hydrogen molecules

This research describes the theoretical study of the adsorption of lithium clusters on graphene and the ability to capture hydrogen molecules. The results of the studied structures showed that the Li₁C₅₄H₁₈]⁺ system is capable of accepting three hydrogen molecules showing adsorption energies of 0.12 eV. On the other hand, it is important to note that in Li_nC₅₄H₁₈] n = 2–6 systems, the lithium atoms that do not interact with the graphene surface, they can adsorb up to four hydrogen molecules. The Li₆C₅₄H₁₈]4H₂ system presented a higher adsorption energy value of 0.31 eV. Finally, the Li–H₂ interactions were characterized by a NBO analysis, which showed that hydrogen atoms are the donors and lithium atoms are the acceptors.