The production of carbon nano-materials by arc discharge under water or liquid nitrogen

Abstract The growth mechanism of carbon nano-materials by arc discharge in water or liquid nitrogen was investigated using a special arc discharge apparatus. High-resolution transmission electron microscopy was used to observe and analyze the products. Results indicated that multi-walled carbon nanotubes (MWCNTs) and carbon onions can be produced by arc discharge in water and liquid nitrogen respectively. Single-walled carbon nanohorns can be produced by arc discharge in liquid nitrogen, and cobalt encapsulated carbon nano-particles can be produced by cobalt catalyzed carbon arc discharge in water. The liquids acted as quenching walls for the nucleation and growth of carbon nano-materials, resulting in the formation of different forms of carbon nano-materials. A cross alternating magnetic field with a frequency 5 Hz can affect the nucleation of nano-materials to form MWCNTs or carbon onions because nucleation time is longer than the periodicity of the magnetic field. Based on the experimental phenomena, a primary physical model was proposed to interpret the growth of nano-materials by arc discharge in liquids.