Nanotubes for charge storage - towards an atomistic model
Nanotubes for charge storage - towards an atomistic model
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DOI：
10.1016/j.electacta.2014.12.031
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发表时间：
2015-04-20
影响因子：
6.6
通讯作者：
Schmickler, Wolfgang
中科院分区：
文献类型：
--
作者：
Mohammadzadeh, Leila;Goduljan, Aleksej;Schmickler, Wolfgang
我们用密度泛函理论研究了碱金属和卤素离子在石墨和金纳米管中的插入。对于直径小于约10埃的管，离子的最佳位置是在管的中心。巴德分析和分析的状态密度给了相互矛盾的结果的电荷的卤素离子，但我们认为，在物理上的理由，他们携带单位负电荷。我们已经计算了原子进入管中电离时的能量。由于系统尺寸小，管的功函数在此过程中发生变化，这使得难以解释这些能量。周围的管非常有效地屏蔽了离子电荷;从而大大减少了离子-离子相互作用，这就解释了为什么窄管比宽管更有效地存储电荷。这些效应对于金比对于石墨管更强。我们定义了一个有效的图像半径的圆柱形管，并计算所经历的离子的图像能量。(C)2014爱思唯尔有限公司版权所有。
We examine the insertion of alkali and halide ions into narrow nanotubes of graphite and gold by density functional theory (DFT). For tubes with diameters less than about 10 angstrom the optimum position of the ion is in the center of the tube. Bader analysis and an analysis of the densities of states gave contradictory results for the charge on the halide ions, but we argue on physical grounds that they carry unit negative charge. We have calculated the energies of inserting the atoms into the tubes, where they are ionized. Because of the small system size the work function of the tubes changes during this process, which makes it difficult to interpret these energies. The surrounding tubes screen the ionic charge very effectively; thereby the ion-ion interactions are strongly reduced, which explains, why narrow tubes store charge more effectively than wider one. These effects are stronger for gold than for graphite tubes. We define an effective image radius of a cylindrical tube, and calculate the image energy experienced by the ions. (C) 2014 Elsevier Ltd. All rights reserved.