Formation of pile networks by long carbon nanotubes from decomposition of CO on Co-Mo film.

We report the formation of pile networks by long carbon nanotubes grown at 700 degrees C from a Co-Mo film on a quartz plate. Carbon monoxide (CO) was used as the carbon source. The networks were formed because the density of catalyst particles on the substrate was low, which resulted in low carbon nanotube density that did not support vertical growth. At the same time, the low carbon nanotube density makes it possible for CO to reach the catalysts on the substrate for continuous growth. No obvious amorphous carbon chunks were observed, suggesting that the pile networks consisted of fairly high-quality, long carbon nanotubes.