Theoretical Study of Hydrogen Storage on Ti-Decorated BC₃ Nanostructures

Hydrogen storage on Ti-decorated BC₃ nanosheet and nanotube have been studied using density functional theory (DFT) calculations. It is found that Ti atoms can stably adsorb on the pristine BC₃ sheet and nanotube without the problem of clustering. The hybridization between Ti d-orbital and BC₃ p-orbital is observed around the Fermi level. From H₂ saturation adsorption calculations, we find that each Ti atom can bind up to four hydrogen molecules on the Ti-decorated BC₃ sheet and (5, 0) nanotube, yielding the same hydrogen storage capacity of 8.2 wt%. Due to the curvature effect of nanotube, the interaction of hydrogen molecules with Ti@BC₃ nanotube is stronger than that of Ti@BC₃ sheet. The charge transfers between H₂ molecules and Ti atom as well as Ti and BC₃ nanostructures are carefully examined.