Manganese-catalyzed surface growth of single-walled carbon nanotubes with high efficiency

We demonstrate that manganese (Mn) can catalyze the growth of single-walled carbon nanotubes (SWNTs) with high efficiency via a chemical vapor deposition process. Dense and uniform SWNT films with high quality were obtained by using a Mn catalyst, as characterized by scanning electron microscopy, Raman spectroscopy, atomic force microscopy, and transmission electron microscopy. Moreover, we found that the surface property of the substrate plays a critical role in the growth efficiency of SWNTs. By deposition of a thin oxide layer (SiO₂ or Al₂O₃) on the top of a SiO ₂/Si substrate, the growth efficiency of SWNTs was dramatically improved. The successful growth of SWNTs by Mn catalyst provides new experimental information for understanding the growth mechanism of SWNTs, which may be helpful for their controllable synthesis.