LAUSR

Abstract The role of two sulfur sources, such as, thiophene and carbon disulfide, on the structure (graphitic layer) of carbon nanotube cotton (CNT-c) has been investigated during floating catalyst chemical vapour deposition (FC-CVD). The CNT-c assembly at 1200 °C with ferrocene and ethanol as catalyst and carbon precursors respectively was found to be predominantly consisting of (a) single-walled carbon nanotubes (SWCNTs) in the presence of carbon disulfide and (b) multi-walled carbon nanotubes (MWCNTs) in the presence of thiophene. The finding was based on detailed characterization using Raman spectroscopy, transmission electron microscopy and scanning electron microscopy. A possible mechanism for having two different structures has been discussed. The experimental results demonstrated that the interaction of sulfur source with the catalyst particle strongly influenced the number of graphitic layers of CNTs in the CNT-c assembly.