Effect of catalytic metals on diameter-controlled growth of single-walled carbon nanotubes: Comparison between Fe and Au

We investigated the effect of catalytic metals on diameter-controlled growth of single-walled carbon nanotubes (SWNTs) using different catalytic nanoparticles. We chose Fe and Au nanoparticles as catalysts for the growth of the SWNTs and compared the experimental results in terms of the diameter control of the SWNTs. Since there is a size relationship between SWNTs and catalysts, our approach involved controlling the size of the catalytic nanoparticles. First, the Fe and Au nanoparticles were monodispersed onto quartz substrates by optimizing the spincasting conditions and were subsequently thermally annealed in order to evaporate the nanoparticles. With the same annealing treatment at 900°C, it was found that the average diameter of the Au decreased more rapidly than that of the Fe nanoparticles. Finally, thin SWNTs were obtained with a much narrower diameter distribution from the evaporated Au nanoparticles than were obtained from the evaporated Fe nanoparticles.