Adsorption of CO molecule on AlN nanotubes by parallel electric field.

The behavior of the carbon monoxide (CO) adsorbed on the external surface of H-capped (6,0) zigzag single-walled aluminum nitride nanotube (AlNNT) was studied using parallel and transverse electric field (strengths 0-140 × 10(-4) a.u.) and density functional calculations. The calculated adsorption energies of the CO/AlNNT complex increased with increasing parallel electric field intensity, whereas the adsorption energy values at the applied transverse electric field show a significant reverse trend. The calculated adsorption energies of the complex at the applied parallel electric field strengths increased gradually from -0.42 eV at zero field strength to -0.80 eV at a field strength of 140 × 10(-4) a.u. The considerable changes in the adsorption energies and energy gap values generated by the applied parallel electric field strengths show the high sensitivity of the electronic properties of AlNNT towards the adsorption of CO on its surface. Analysis of structural parameters indicates that the nanotube is resistant to external electric field strengths. The dipole moment variations in the complex show a significant change in the presence of parallel and transverse electric fields, which results in much stronger interactions at higher electric field strengths. Additionally, the natural bond orbital charges, quantum molecular descriptors, and molecular orbital energies of the complex show that the nanotube can absorb CO molecule in its pristine form at a high applied parallel electric field, and that the nanotube can be used as a CO storage medium.