An ab-initio study of hydrogen storage performance of Si2BN nanotubes decorated with group 8B transition metals

Abstract

Binding of group 8B transition metals (TMs) on Si2BN nanotubes and the adsorption of H2 molecules on TM-decorated Si2BN nanotubes are investigated in the framework of first principles-based density functional theory (DFT). Our results show the adsorption energy of H2 molecule on TM-decorated Si2BN nanotube (−2.57 eV) to be greater than those of the other reported adsorbents. The enhancement of the adsorption property is attributed to the structural deformation and the induced charge transfer between TM–decorated Si2BN nanotube and the hydrogen molecule. Our findings reveal the TM–decorated Si2BN nanotubes to be highly sensitive to the presence of H2 molecules. Additionally, we also investigated the adsorption process of multiple H2 molecules on TM-decorated Si2BN nanotubes. Our observations lead us to surmise that the maximum storage number of H2 molecules adsorbed over the TM-decorated Si2BN nanotubes is four. These results suggest useful potential for the TM-decorated Si2BN nanotube to be considered as an appropriate medium for hydrogen storage.