Stability and Electronic Properties of the Adsorption of Molecular Hydrogen on Metal-containing Single-walled Carbon Nanotubes

The binding ability and hydrogen storage capacity of nitrogen doped carbon nanotube with divacancy (4NDCNxNT) that is decorated with transition metals was investigated based on density functional theory calculations. Results indicate that scandium shows an ideal reversible hydrogen binding capability with promising system-weight efficiency compared with other transition metals when functionalized with 4ND-CNxNT. The (Sc/4ND)(10)-CNxNT can store up to 50H(2) molecules, corresponding to a maximum gravimetric density of 5.8 wt%. Detailed structural stability and electronic properties were reported as hydrogen molecules were absorbed. It takes about 0.16 eV/H-2 to add one H-2 molecule, which assures reversible storage of H-2 molecules under ambient conditions.