Effect of Different Catalysts on Growth of CNx Nanotubes by Thermal Decomposition

CNx nanotubes was synthesized by thermal decomposition ethylenediamine catalyzed by pure iron, cobalt, nickel, and ferrocene. The effect of the catalyst on the CNx nanotubes’ morphology and yield was studied. The catalysis growth mechanism was also discussed. The CNx nanotubes with the “bamboo-like” structure and lower yield are produced when iron or ferrocene is used as the catalyst, whereas the curved CNx nanotubes with many pleats through the nanotube walls and higher yield are generated when cobalt is used. The CNx nanotubes catalyzed by nickel are only helix tubes with the diameter of about 500 nm. Raman spectroscopy studies show that the CNx nanotubes catalyzed by ferrocene have a worse crystallinity due to a higher nitrogen incorporation.