Growth of Single-Walled Carbon Nanotubes from Pt catalysts by the Alcohol Gas Source Method under Low Ethanol Pressure: Growth Temperature Dependence

Abstract

The growth of single-walled carbon nanotubes (SWNTs) was carried out on SiO 2 /Si substrates with Pt catalysts between 500 and 800ºC under various ethanol pressures using an alcohol gas source method, a type of cold-wall chemical vapor deposition (CVD). The grown SWNTs were characterized by Raman spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Irrespective of the growth temperature, the optimal ambient ethanol pressures were between 1×10 -4 and 1×10 -2 Pa. In the SWNT growth at 700ºC, Raman results showed that the diameters of SWNTs grown with Pt catalysts were below 1.4 nm, which was much smaller than that grown with conventional Co catalyst, and that the diameters of SWNTs from Pt decreased as the growth temperature was reduced. In addition, we observed that the catalyst lifetime of Pt was longer than Co. We demonstrated that Pt is an efficient catalyst to grow SWNTs with small diameters.