Synthesis of multiwalled carbon nanotubes at temperatures below 300°C by hot-filament assisted chemical vapor deposition

Synthesis of multiwalled carbon nanotubes was attempted at low temperatures by chemical vapor deposition using a hot filament. Ethanol was used as a carbon source. As a catalyst, particles produced by scratching a cobalt plate with sandpaper were mixed with zeolite powder. We successfully synthesized multiwalled carbon nanotubes at 280 degrees C. The diameter of the nanotubes was in the range of 8-20 nm. The reaction was carried out at atmospheric pressure, therefore we did not use a vacuum pump in the synthesis. We also did not use inflammable and explosive gas. Thus, we have succeeded in synthesizing multiwalled carbon nanotubes at low temperatures using very simple and low-risk equipment.