Single-Wall Carbon Nanotubes and Single-Wall Carbon Nanohorns

Abstract

Metal catalysts take forms of nanometer-sized particles in the condensed carbon phase and catalyze the growth of single-wall carbon nanotubes at about 1200 °C. The good metal catalysts in forming single-wall carbon nanotubes must satisfy at least three conditions: (1) be a good graphitization catalyst, (2) have low solubility in graphite, and (3) have a stable crystallographic orientation on graphite. The large-scale production of single-wall carbon nanotubes is difficult. On the other hand, single-wall carbon nanohorns (SWNH) are formed with a high purity of 90% and a yield of 90% at room temperature. The SWNHs are nanometer-scale graphene tubules and form aggregates with diameters of about 80–100 nm. The SWNH aggregates might be useful in adsorption/storage of various gases.