密度泛函理论研究钠原子在不同直径碳纳米管内部和外部的吸附

Investigation of Sodium Atom Adsorption on the Interiors and Exteriors of Carbon Nanotubes with Different Diameters Based on the Density Functional Theory

运用密度泛函理论(DFT)研究钠原子在不同直径的碳纳米管内部和外部的吸附。选取(8,0)～(22,0)手性的碳纳米管模拟不同直径的碳纳米管。在碳纳米内部,钠原子能吸附在碳纳米管中心位置或靠近管壁的位置;而在碳纳米外部,钠原子仅能吸附在靠近碳纳米管壁位置。对于不同直径的碳纳米管,钠原子在(8,0)手性碳纳米管内部吸附能最强,这是由于钠原子几乎位于(8,0)碳纳米管的中心位置,导致钠原子与碳纳米管上多个碳环有相互作用。此外研究了钠原子的吸附距离,Mulliken布局分布,以及吸附钠原子引起体系电荷密度的重新分布。

The density functional theory(DFT)is proposed to study sodium atom adsorption on the interiors and exteriors of carbon nanotubes with different diameters.Carbon nanotubes with varing diameters are modeled with those ranging from the chiral vector(8,0)to the chiral vector(22,0).The sodium atom can be adsorbed at.the center or near the sidewall for the interior of a carbon nanotube.However,it can be only adsorbed near the sidewall for the exterior of the carbon nanotube.For different diameters of carbon nanotubes,the strongest adsorption energy of sodium atom adsorbed in the interior of the(8,0)carbon nanotube.This is because the sodium atom almost locates at the center of the(8,0)carbon nanotube,leading to interaction between the sodium atom and multiple carbon rings of the carbon nanotube.Moreover,the present paper investigates the adsorption distance of the sodium atom,the Mulliken population,and the system of the redistri-bution of the electron density induced by the sodium atom adsorption.