Hydrogen adsorption by tungsten carbide nanotube

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 3.94eV and a binding distance of 1.7Å. Hydrogen molecule also favors the W atop site energetically. The calculated binding energy and distance are 0.44eV and 1.85Å, respectively. The authors’ studies demonstrate that the tungsten carbide nanotube could be a promising material for energy storage.