Plasma Nanoscience Centre Australia, CSIRO Materials Science and Engineering, Lindfield, New South Wales 2070, Australia.
J Am Chem Soc. 2012 Apr 4;134(13):6018-24. doi: 10.1021/ja300805s. Epub 2012 Mar 23.
Precisely controlled reactive chemical vapor synthesis of highly uniform, dense arrays of vertically aligned single-walled carbon nanotubes (SWCNTs) using tailored trilayered Fe/Al(2)O(3)/SiO(2) catalyst is demonstrated. More than 90% population of thick nanotubes (>3 nm in diameter) can be produced by tailoring the thickness and microstructure of the secondary catalyst supporting SiO(2) layer, which is commonly overlooked. The proposed model based on the atomic force microanalysis suggests that this tailoring leads to uniform and dense arrays of relatively large Fe catalyst nanoparticles on which the thick SWCNTs nucleate, while small nanotubes and amorphous carbon are effectively etched away. Our results resolve a persistent issue of selective (while avoiding multiwalled nanotubes and other carbon nanostructures) synthesis of thick vertically aligned SWCNTs whose easily switchable thickness-dependent electronic properties enable advanced applications in nanoelectronic, energy, drug delivery, and membrane technologies.
采用定制的三层 Fe/Al2O3/SiO2 催化剂，精确控制反应性化学气相合成高度均匀、密集排列的垂直取向单壁碳纳米管（SWCNTs）。通过调整支撑 SiO2 层的二次催化剂的厚度和微观结构，可以生产出超过 90%的厚纳米管（直径大于 3nm）。通常被忽视的这种调整，基于原子力微分析提出的模型表明，这导致了相对较大的 Fe 催化剂纳米粒子的均匀和密集排列，在这些纳米粒子上，厚的 SWCNTs 成核，而小的纳米管和非晶碳则被有效地蚀刻掉。我们的结果解决了一个长期存在的问题，即选择性（同时避免多壁纳米管和其他碳纳米结构）合成厚的垂直取向 SWCNTs，其易于切换的厚度相关的电子性能使其能够在纳米电子、能源、药物输送和膜技术中得到先进的应用。
