Atomic hydrogen adsorption on freestanding α-borophene nanoribbons for hydrogen spillover applications: Insights from density functional theory calculations

Abstract

In this work, we probed the applicability of α-borophene nanoribbon as a spillover hydrogen host material using density functional theory (DFT) calculations. It is found that all top sites, along the edges and on the planar surface, are appropriate for hydrogen physisorption. On the other hand, the hollow site which is a defining feature of the α-borophene nanoribbon, was found to be an unstable adsorption site for hydrogen, and does not act as a trap site for hydrogen atom. Density of states calculations show that the broadening of the hydrogen 1s states made it possible for a good hybridization with the boron 2p states, allowing for such a moderate hydrogen physisorption. The resulting moderate adsorption energies indicate good hydrogen migration properties, making α-borophene nanoribbon a very good candidate material for spillover hydrogen applications and could be utilized as a key material for overall hydrogen storage.