Hydrogen confined in single-wall carbon nanotubes: Anisotropy effects on ro-vibrational quantum levels.
Hydrogen confined in single-wall carbon nanotubes: Anisotropy effects on ro-vibrational quantum levels
J. Suárez, F. Huarte-Larrañaga.
J. Chem. Phys. 137 (2012) 064320.
Energy spectrum pf the H2 molecule in the ground vibrational state and confined in a carbon nanotube of chirality (8,0).
Different colored lines correspond to different rotational states.
This article presents the quantum dynamics study in which we obtained the energy levels of the hydrogen molecule encapsulated in the inner cavity of a single walled carbon nanotube. The effects of confinement in nanostructures have awakened a great amount of interest in the recent past. In addition to this, carbon nanotubes have shown an outstanding capability to encapsulate molecules in nearly monodimensional environments and this feature could be important in processes such as hydrogen physisorption. The simulations we have carried out include explicitly all degrees of freedom of the confined molecule, revealing how vibrational motion is affected by the confining potential generated by the walls of the nanostructures. Previous works that neglected this degree of freedom did not observe this feature. However, the most important effects are the molecule rotation and the appearance of a quantized translational motion. We have also analyzed the dependence of the confinement effects on the interaction potential by tuning the different parameters in the empirical carbon-hydrogen potential.