Hydrogen adsorption by tungsten carbide nanotube

Abstract

First-principles calculations based on density functional theory were carried out to investigate single-wall tungsten carbide nanotubes and their applications to energy storage, such as hydrogen storage and fuel cell. The pristine tungsten carbide nanotube was metallic. The W atop site is the most stable adsorption site for hydrogen atom, with a binding energy of 3.94 eV and a binding distance of 1.7 Å. Hydrogen molecule also favors the W atop site energetically. The calculated binding energy and distance are 0.44 eV and 1.85 Å, respectively. The authors' studies demonstrate that the tungsten carbide nanotube could be a promising material for energy storage. © 2007 American Institute of Physics.