Gas-phase catalytic growth of single-walled carbon nanotubes from carbon monoxide

Single-walled carbon nanotubes (SWNTs) have been produced in a gas-phase catalytic process. Catalysts for SWNT growth form in situ by thermal decomposition of iron pentacarbonyl in a heated flow of carbon monoxide at pressures of 1–10 atm and temperatures of 800–1200°C. The SWNT yield and diameter distribution can be varied by controlling the process parameters, and SWNTs as small as 0.7 nm in diameter, the same as that of a C60 molecule, have been generated. This process shows great promise for bulk production of carbon nanotubes.