Si2BN monolayers as promising candidates for hydrogen storage

Abstract

Hydrogen storage properties of the pure Si₂BN monolayer were studied using density functional theory calculations. The interaction of H₂ molecules with the Si₂BN monolayer is weak and of electrostatic nature. The average hydrogen adsorption energies are within the ideal range of practical applications (0.187–0.214 eV), and the consecutive adsorption energies indicate that the spontaneous adsorption of H₂ molecules on the Si₂BN monolayer can occur. The hydrogen gravimetric density of the periodic Si₂BN monolayer reaches 8.5 wt%, which exceeds the standard of 6.0 wt% set by the US Department of Energy (DOE) by the year 2020. The estimated desorption temperatures show the desirable properties for the long term recycling of the Si₂BN storage medium. Thus, our results show that the Si₂BN monolayer is a promising candidate for molecular hydrogen storage.