Plasma jet assisted synthesis of carbon nanotubes by in-situ bimetallic catalysts

Carbon nanotubes were synthesized in a methane plasma by using Fe_2O_3/Ni as catalysis. Methane is pyrolyzed efficiently into nano-carbon and H_2 by the plasma jet under atmospheric pressure, during which Fe_2O_3 is reduced by H_2 to form nanometer sized metallic particles, which together with Ni are used as bimetallic catalysts for the preparation of nanotubes. The carbon nanotubes were examined using TEM and chemical element (analysis), etc. Results show that the carbon nantotubes present an appearance of entangled morphologies with (outer) diameters of 10-30nm, length of several hundred nanometers, and the yield is about 75%. Compared with the single catalyst, the bimetallic catalyst is advantageous for the mass production of carbon nanotubes.