School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
Nat Chem. 2011 Aug 14;3(9):732-7. doi: 10.1038/nchem.1115.
Although the outer surface of single-walled carbon nanotubes (atomically thin cylinders of carbon) can be involved in a wide range of chemical reactions, it is generally thought that the interior surface of nanotubes is unreactive. In this study, we show that in the presence of catalytically active atoms of rhenium inserted into nanotubes, the nanotube sidewall can be engaged in chemical reactions from the inside. Aberration-corrected high-resolution transmission electron microscopy operated at 80 keV allows visualization of the formation of nanometre-sized hollow protrusions on the nanotube sidewall at the atomic level in real time at ambient temperature. Our direct observations and theoretical modelling demonstrate that the nanoprotrusions are formed in three stages: (i) metal-assisted deformation and rupture of the nanotube sidewall, (ii) the fast formation of a metastable asymmetric nanoprotrusion with an open edge and (iii) a slow symmetrization process that leads to a stable closed nanoprotrusion.
虽然单壁碳纳米管（原子级薄的碳圆柱体）的外表面可以参与广泛的化学反应，但通常认为纳米管的内表面是无反应性的。在这项研究中，我们表明，在插入纳米管中的铼催化活性原子存在的情况下，纳米管侧壁可以从内部参与化学反应。在 80keV 下工作的校正像差的高分辨率透射电子显微镜允许在环境温度下实时以原子级实时可视化纳米级中空突起在纳米管侧壁上的形成。我们的直接观察和理论建模表明，纳米突起是分三个阶段形成的：（i）金属辅助的纳米管侧壁变形和破裂，（ii）快速形成具有开放边缘的亚稳态不对称纳米突起，以及（iii）导致稳定的闭合纳米突起的缓慢对称化过程。
