Carbon nanotubes from the dissociation of C2Cl4using a dc thermal plasma torch

Carbon nanotubes (CNTs) are produced using a 100 kW dc non-transferred plasma torch and C2Cl4 as the carbon precursor. Catalytic metallic nanoparticles are generated in situ using the tungsten metal vapours emitted by the electrode erosion process. Large quantities of multi-walled carbon nanotubes (MWNTs) and spherical (onion-like) carbon structures are observed under FE-SEM and TEM. Preliminary results are given here on the effect of the type and pressure of the gas in the reactor on the zone of CNT nucleation. A large amount of CNTs, over 50 µm in length, is observed to grow within the torch nozzle at 0.26 atm pressure in helium and argon. Increasing the pressure to 0.66 atm in both gases has the effect of pushing the CNT production downstream in the gas phase within the main reactor.