Synthesis optimisation and characterisation of multiwalled carbon nanotubes produced by spray pyrolysis of hexane

Multiwalled carbon nanotubes have been prepared by spray pyrolysing of hexane as the carbon source in the presence of ferrocene as catalyst precursor using H₂ as the carrier gas. The process has been studied as a function of various experimental parameters in order to obtain optimal preparation conditions. The morphology and structure of the samples were characterised by scanning electron microscopy, transmission electron microscopy, energy dispersive spectra and Raman spectroscopy analyses. The optimum synthesis parameters have obtained including the sublimation temperature of 140°C, the growth temperature of 900°C, the growth time of 45 min, the ferrocene concentration in hexane of 2·5 g/100 mL, the flow rate of hexane and H₂ of 2 cm³ min^–1 and 300 sccm respectively.