Does water dope carbon nanotubes?
Does water dope carbon nanotubes?
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DOI：
10.1063/1.4898712
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发表时间：
2014-10-28
影响因子：
4.4
通讯作者：
Mostofi, Arash A.
中科院分区：
文献类型：
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作者：
Bell, Robert A.;Payne, Michael C.;Mostofi, Arash A.
我们计算了水分子物理吸附对碳纳米管 (CNT) 电子电荷密度的长程扰动。我们发现，主要效应是由于水分子偶极矩引起的极化而导致碳纳米管中的电荷重新分布。研究发现电荷重新分布发生在大于 30 埃的长度范围内，这凸显了大规模模拟的必要性。通过将我们的完全第一原理计算与使用经典静电模型处理水分子引起的扰动的计算进行比较，我们估计 CNT 和水之间的电荷转移可以忽略不计（每个水分子不超过 10(-4) e）。因此，我们得出结论，水不会显着掺杂碳纳米管，这一结论与水分子和碳纳米管的相关能级的不良对齐一致。之前的计算表明，水掺杂碳纳米管很可能是由于对小型超级电池中马利肯电荷分配的误解造成的。 (C) 2014 AIP 出版有限责任公司。
We calculate the long-range perturbation to the electronic charge density of carbon nanotubes (CNTs) as a result of the physisorption of a water molecule. We find that the dominant effect is a charge redistribution in the CNT due to polarisation caused by the dipole moment of the water molecule. The charge redistribution is found to occur over a length-scale greater than 30 angstrom, highlighting the need for large-scale simulations. By comparing our fully first-principles calculations to ones in which the perturbation due to a water molecule is treated using a classical electrostatic model, we estimate that the charge transfer between CNT and water is negligible (no more than 10(-4) e per water molecule). We therefore conclude that water does not significantly dope CNTs, a conclusion that is consistent with the poor alignment of the relevant energy levels of the water molecule and CNT. Previous calculations that suggest water n-dopes CNTs are likely due to the misinterpretation of Mulliken charge partitioning in small supercells. (C) 2014 AIP Publishing LLC.