接枝羧基的有限长碳纳米管电子结构的第一性原理研究

The first-principles calcultion of the electronic structure of finite length carbon nanotubes grafted by carboxyl

基于局域密度泛函理论,采用第一性原理方法,建立了对(5,5)型和(9,0)型有限长碳纳米管接枝羧基官能团的原子模型,通过计算其电子分布和态密度的变化,讨论羧基官能团对碳纳米管电子结构和电子输运特性的影响.计算表明,接枝羧基的碳纳米管,其电子结构明显改变,其费米能级上的电子态密度下降;最高占据轨道上的非定域程度减弱,致使电子输运性能呈下降趋势.

We report the first-principles calculation of the electronic distribution and the density of states （DOS） of the armchair （5,5） and zigzag （9,0） single-walled carbon nanotubes （SCNTs） grafted by carboxyl within the framework of density-functional-theory （DFT）. It was found that the electronic structure of the SCNTs changes significantly due to the graft, namely, the electron density of states near Fermi level and the delocalized degree of the highly occupied molecular orbital decline greatly with increase of the number of carboxylic functional groups grafted. This suggests that the graft weakens the electronic transport properties of SCNTs.