Chirality-dependent combustion of single-walled carbon nanotubes
Chirality-dependent combustion of single-walled carbon nanotubes
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DOI：
10.1021/jp072359g
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发表时间：
2007-07-12
影响因子：
3.7
通讯作者：
Kataura, Hiromichi
中科院分区：
文献类型：
--
作者：
Miyata, Yasumitsu;Kawai, Takazumi;Kataura, Hiromichi
利用光致发光和拉曼光谱研究了单壁碳纳米管（SWCNTs）在空气和过氧化氢中氧化过程中的手性燃烧。在空气氧化条件下，具有更高手性角和更小直径的单壁碳纳米管被观察到更快地分解。从反应速率分析确定每个手性指数的分解速率，并且发现该反应受沿C-C键的“局部曲率半径”沿着控制。利用第一性原理计算得到了10种单壁碳纳米管在与氧分子环加成后发生C-C键断裂的反应势垒。发现势垒高度依赖于局部曲率半径，这与实验结果吻合得很好。另一方面，对于在过氧化氢中的氧化反应，氧自由基分解较小半径的单壁碳纳米管更迅速，没有任何手性选择。因此，两个不同的手性分布的单壁碳纳米管具有相似的直径，得到这些氧化过程。
The chirality-dependent combustion of single-walled carbon nanotubes (SWCNTs) during oxidation in both air and hydrogen peroxide was investigated using photoluminescence and Raman spectroscopy. Under air oxidation conditions, SWCNTs with a higher chiral angle and smaller diameter were observed to decompose more rapidly. The decomposition rate of each chiral index was determined from the reaction rate analysis, and it was found that the reaction is governed by a "local curvature radius" along the C-C bond. The reaction barriers for breaking the C-C bonds after cycloaddition with oxygen molecules were obtained for 10 types of SWCNTs using first-principles calculations. The barrier heights were found to depend on the local curvature radius, which showed good agreement with the experimental results. On the other hand, for the oxidation reaction in hydrogen peroxide, oxygen radicals decomposed the smaller-radius SWCNTs more rapidly without any chirality selection. As a result, two different chirality distributions for SWCNTs with similar diameters were obtained by these oxidation processes.