Theoretical Investigation of Hydrogen Adsorption on Ultra-Small Carbon Nanotubes

The hydrogen adsorption on the surface of ultra small radius (3,0) was investigated. The structural and electronic changes due to physical and chemical adsorption were studied by density functional theory based calculations. The initial adsorptive orientation of hydrogen molecules with respect to the nanotube surface was obtained by the realistic molecular dynamics simulations. The resulted stable configuration was considered as the starting point for the rest electronic analysis. The total energies, atomic charges, and energy band gaps were calculated at three states, namely the pristine, physisorbed and hydrogenated (3,0) single walled carbon nanotube. The higher chemisorbed energy, in comparison with the general larger diameter carbon nanotubes, was attributed to the strong curvature effect of this ultra narrow nanotube. Both band structure and molecular orbital analysis clearly showed that chemisorption makes the nanotube conducting along the tube axis.

کلیدواژه ها:

Ultra small nanotube ، Hydrogen adsorption ، MD simulations ، DFT