University of Vienna, Faculty of Physics, 1090 Wien, Austria.
Nanoscale. 2018 Dec 7;10(45):21254-21261. doi: 10.1039/c8nr06925e. Epub 2018 Nov 12.
Double-walled carbon nanotubes (DWCNTs) combined the advantages of multi-walled (MW-) and single-walled (SW-) CNTs can be obtained by transforming the precursors (e.g. fullerene, ferrocene) into thin inner CNTs inside SWCNTs as templates. However, this method is limited since the DWCNT yield is strongly influenced by the filling efficiency (depending on the type of the filled molecules), opening and cutting the SWCNTs, and the diameter of the host SWCNTs. Therefore, it cannot be applied to all types of SWCNT templates. Here we show a universal route to synthesize ultra-thin DWCNTs via making SWCNTs stable at high temperature in vacuum. This method applies to different types of SWCNTs including metallicity-sorted ones without using any precursors since the carbon sources were from the reconstructed SWCNTs and the residue carbons. The resulting DWCNTs are with high quality and the yield of inner tubes is comparable to/higher than that of the DWCNTs made from the transformation of ferrocene/fullerene peapods.
双壁碳纳米管（DWCNTs）结合了多壁（MW-）和单壁（SW-）碳纳米管的优点，可以通过将前体（例如富勒烯、二茂铁）转化为 SWCNT 内部的薄内 CNT 作为模板来获得。然而，这种方法受到限制，因为 DWCNT 的产率强烈受到填充效率（取决于填充分子的类型）、SWCNT 的打开和切割以及宿主 SWCNT 的直径的影响。因此，它不能应用于所有类型的 SWCNT 模板。在这里，我们展示了一种通过在真空中将 SWCNTs 稳定在高温下来合成超薄壁 DWCNTs 的通用方法。该方法适用于不同类型的 SWCNTs，包括无需使用任何前体的金属性分类 SWCNTs，因为碳源来自重构的 SWCNTs 和残余碳。所得到的 DWCNTs 质量很高，内管的产率与/高于由二茂铁/富勒烯豆荚转化而来的 DWCNTs 的产率。
