Continuous production of aligned carbon nanotubes: a step closer to commercial realization

High-purity aligned multi-walled carbon nanotubes (MWNTs) were synthesized through the catalytic decomposition of a ferrocene–xylene mixture at ∼675°C in a quartz tube reactor and over quartz substrates, with a conversion of ∼25% of the total hydrocarbon feedstock. Under the experimental conditions used, scanning electron microscope images reveal that the MWNT array grows perpendicular to the quartz substrates at an average growth rate of ∼25 μm/h. A process of this nature which does not require preformed substrates, and which operates at atmospheric pressure and moderate temperatures, could be scaled up for continuous or semi-continuous production of MWNTs.