High-yield synthesis of multi-walled carbon nanotubes by arc discharge in liquid nitrogen

Synthesis of multi-walled carbon nanotubes (MWNTs) by arc discharge in liquid nitrogen is reported. As liquid nitrogen substituted both vacuum and cooling systems, high-quality MWNTs were produced at a low cost. The content of the MWNTs can be as high as 70% of the reaction product. Auger-spectroscopy analysis revealed that no nitrogen is incorporated in the MWNTs. This method can be an economical route for the mass production of highly crystalline MWNTs.