Takakura Akira, Nishihara Taishi, Harano Koji, Cretu Ovidiu, Tanaka Takeshi, Kataura Hiromichi, Miyauchi Yuhei
Institute of Advanced Energy, Kyoto University, Uji, Kyoto, 611-0011, Japan.
Center for Basic Research on Materials, National Institute for Materials Science, Tsukuba, Ibaraki, 305-0044, Japan.
Nat Commun. 2025 Feb 5;16(1):1093. doi: 10.1038/s41467-025-56389-6.
Atomically precise coalescence of graphitic nanocarbon molecules is one of the most challenging reactions in sp carbon chemistry. Here, we demonstrate that two carbon nanotubes with the same chiral indices (n, m) are efficiently coalesced into a single (2n, 2 m) nanotube with preserved chiral angles via heat treatment at less than 1000 °C. The (2n, 2 m) nanotubes constitute up to ≈ 20%-40% of the final sample in the most efficient case. Additional optical absorption peaks of the (2n, 2 m) nanotubes emerge, indicating that the reaction occurs over the entire sample. The reaction efficiency strongly depends on the chiral angle, implying that C-C bond cleavage and recombination occurs sequentially. Furthermore, the reaction occurs efficiently even at 600 °C in an atmosphere containing trace amounts of oxygen. These findings offer routes for the structure-selective synthesis of large-diameter nanotubes and modification of the properties of nanotube assemblies via postprocessing.
石墨纳米碳分子的原子精确聚结是sp碳化学中最具挑战性的反应之一。在此，我们证明了具有相同手性指数（n，m）的两根碳纳米管通过在低于1000°C的温度下进行热处理，能有效地聚合成一根具有保留手性角的（2n，2m）纳米管。在最有效的情况下，（2n，2m）纳米管在最终样品中所占比例高达约20%-40%。（2n，2m）纳米管出现了额外的光吸收峰，表明该反应在整个样品中发生。反应效率强烈依赖于手性角，这意味着碳-碳键的断裂和重组是依次发生的。此外，即使在含有痕量氧气的气氛中，该反应在600°C时也能高效发生。这些发现为大直径纳米管的结构选择性合成以及通过后处理对纳米管组件性能进行改性提供了途径。
