We perform the density-functional and quantum chemical calculations of adsorption of a hydrogen molecule to various kinds of single-walled carbon nanotubes (SWNT’s). The potential energy barrier height (PBH) for the dissociative adsorption of a hydrogen molecule onto the outer wall of a nanotube decreases as the tube diameter decreases. In contrast, the PBH for H2 penetration into an open-ended nanotube increases as the tube diameter decreases, independent of the atomic geometry, i.e., zigzag or armchair structures. H2, however, cannot adsorb to the inner wall of any type of nanotube. These results on the structure-dependent H2 adsorption to SWNT’s are reasonably explained by the sp2 - sp3 rehybridization caused by the interaction between the adsorbing hydrogen and carbon atoms of SWNT’s.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 23 Mar 2001|