Investigation on the temperature-dependent growth rate of carbon nanotubes using chemical vapor deposition of ferrocene and acetylene

Carbon nanotubes (CNTs) were synthesized using chemical vapor deposition of ferrocene and acetylene in the temperature range 600-800 °C. The growth rate increases exponentially with the temperature, providing an activation energy 30 kcal/mol which is close to the diffusion energy of carbons in the bulk iron metal. We compared the growth rate with those of the CNTs grown using other thermal methods reported previously and suggest a simple kinetic model to explain the growth rate depending on the method. The supply rate of C atoms in gas phase would influence the growth rate of CNTs.