Single-wall nanotubes produced by metal-catalyzed disproportionation of carbon monoxide

Isolated single-wall carbon nanotubes (SWNT) were grown by disproportionation of carbon monoxide at 1200 degrees C, catalyzed by molybdenum particles a few nanometers in size. The tube diameters, ranging from 1 to 5 nm, closely correlated with the size of the catalytic particle found attached to the tube end. This result represents the first experimental evidence of SWNT produced by pre-formed catalytic particles. A mechanism for nucleation that is quite distinct from our recently proposed mechanism of SWNT produced by laser vaporization is advanced for formation of SWNT in the present case.