Department of Electronic Engineering, Tohoku University, Aoba 6-6-05, Aramaki, Aoba-ku, Sendai, 980-8579, Japan.
Department of Materials Engineering, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan.
Sci Rep. 2017 Sep 11;7(1):11149. doi: 10.1038/s41598-017-11712-0.
Chirality-selective synthesis of single-walled carbon nanotubes (SWNTs) has been a research goal for the last two decades and is still challenging due to the difficulty in controlling the atomic structure in the one-dimensional material. Here, we develop an optimized approach for controlling the chirality of species by tuning the oxidation degree of Co catalyst. Predominant synthesis of (6,4) SWNTs is realized for the first time. The detailed mechanism is investigated through a systematic experimental study combined with first-principles calculations, revealing that the independent control of tube diameter and chiral angle achieved by changing the binding energy between SWNTs (cap and tube edge) and catalyst causes a drastic transition of chirality of SWNTs from (6,5) to (6,4). Since our approach of independently controlling the diameter and chiral angle can be applied to other chirality species, our results can be useful in achieving the on-demand synthesis of specific-chirality SWNTs.
手性选择性合成单壁碳纳米管（SWNTs）是过去二十年来的研究目标，但由于在一维材料中难以控制原子结构，因此仍然具有挑战性。在这里，我们通过调整 Co 催化剂的氧化程度，开发了一种优化的方法来控制手性。首次实现了（6,4）SWNTs 的主要合成。通过系统的实验研究与第一性原理计算相结合，详细研究了该机制，揭示了通过改变 SWNTs（帽和管边缘）与催化剂之间的结合能来独立控制管径和手性角，导致 SWNTs 的手性从（6,5）到（6,4）发生剧烈转变。由于我们独立控制直径和手性角的方法可应用于其他手性物质，因此我们的结果可有助于按需合成特定手性的 SWNTs。
