Controlling the carbon nanotube type with processing parameters synthesized by floating catalyst chemical vapour deposition

Abstract

Abstract Single and multi-walled carbon nanotubes have been synthesized by floating catalyst chemical vapour deposition technique. Methane, argon, ferrocene and sulphur were used as carbon source, inert gas, catalyst and promoter, respectively. The types of carbon nanotubes (single or multi-walled) were governed by a variety of experimental factors: the ferrocene flow rate, methane flow rate, sulfur flow rate, argon flow rate and reaction temperature. The optimization of the process parameters was carried out to find the parameter 'islands' for the selective formation of single or multiwalled carbon nanotubes. The characterization was carried out by transmission electron microscopy, thermo gravimetric analysis and Raman spectroscopy. A high hydrogen flow rate, low methane flow rate and high sulfur flow rate were crucial factors for selective synthesis of single walled carbon nanotubes. This work provides methodology for optimization of processing parameters for synthesizing high purity single or multi walled carbon nanotubes