Zhang Shuchen, Lin Dewu, Liu Weiming, Yu Yue, Zhang Jin
Center for Nanochemistry, Beijing Science and Engineering Center for Nanocarbons, Beijing National Laboratory for Molecular Sciences, Key Laboratory for the Physics and Chemistry of Nanodevices, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China.
Small. 2019 Nov;15(46):e1903896. doi: 10.1002/smll.201903896. Epub 2019 Sep 26.
Currently, designing solid catalysts at high temperature is the main strategy to realize single-walled carbon nanotubes (SWNTs) with specific chirality, meaning it is very hard and challenging to create new catalysts or faces to fit new chirality. However, low temperatures make most catalysts solid, and developing solid catalysts at low temperature is desired to realize chirality control of SWNTs. A rational approach to grow SWNTs array with different chiralities on same solid Co catalysts at low temperature (650 °C) is herein put forward. Using solid Co catalysts, near-armchair (10, 9) tubes horizontal array with ≈75% selectivity and (12, 6) tubes array with ≈82% are realized by adopting a small amount of ethanol and large amount of CO respectively. (10, 9) tubes are enriched for thermodynamic stability and (12, 6) tubes for kinetics growth rate. Both kinds of tubes show a similar symmetry to the Co (1 1 1) face with threefold symmetry for the symmetry matching nucleation mechanism proposed earlier. This method provides a new strategy to study the nucleation mechanism and more possibilities for preparing new solid catalysts to control the structure of SWNTs.
目前，在高温下设计固体催化剂是实现具有特定手性的单壁碳纳米管（SWNTs）的主要策略，这意味着创建新的催化剂或表面以适应新的手性非常困难且具有挑战性。然而，低温会使大多数催化剂固化，因此希望在低温下开发固体催化剂以实现SWNTs的手性控制。本文提出了一种在低温（650℃）下在相同的固体Co催化剂上生长具有不同手性的SWNTs阵列的合理方法。使用固体Co催化剂，通过分别采用少量乙醇和大量CO，实现了近扶手椅型（10,9）管的水平阵列，选择性约为75%，以及（12,6）管的阵列，选择性约为82%。（10,9）管因热力学稳定性而富集，（12,6）管因动力学生长速率而富集。两种管对于先前提出的对称匹配成核机制都显示出与Co（1 1 1）面相似的三重对称性。该方法为研究成核机制提供了一种新策略，并为制备新的固体催化剂以控制SWNTs的结构提供了更多可能性。
