椅型碳纳米管吸附氢原子电子结构的密度泛函研究

采用密度泛函方法对氢原子在(5,5)椅型碳纳米管上的吸附进行了研究, 分别考察了氢原子覆盖度为5%和10%时的构型和吸附能. 研究结果表明, H原子吸附在管外壁要比管内壁能量上更为有利, 同时第二个H原子倾向于吸附在前一个H原子的吸附位置邻近的碳原子上. 由能带计算结果得知, 吸附一个H原子时, 椅型碳纳米管将由导体转变为半导体; 当第二个H原子处在偶数位时, 纳米管仍保持较好的导电性能, 而吸附在奇数位时将使管的传输能力减弱. 本文进一步通过分析纳米管(共轭体系的分布情况对管传输性质的变化进行解释.

Density Functional Study on the Electronic Structures of the Hydrogen-Adsorbed Armchair Carbon Nanotube

The adsorption of atomic hydrogen on (5,5) armchair carbon nanotube has been studied by using density functional theory, and the geometries and adsorption energies for the 5% and 10% coverage of H atoms have been investigated. The calculated results indicate that, the adsorption of H at the exterior is energetically favorable than that at the interior, and the second H atom prefers to be adsorbed at the carbon sites near the first one. By analyzing the band structures, it is known that after the adsorption of the first H atom, the armchair nanotube will become semiconductor. When the second H atom is adsorbed at the even site, the tube keeps its conductive characteristic, while the transfer ability of this tube is weaker for the case at odd site. The change of the transport property can be explained by examining the arrangement of the ( conjugation of the carbon nanotube.