Synthesis of multiwalled carbon nanotubes from carbon black

We describe a method to produce high-crystalline quality multiwalled carbon nanotubes from carbon black. By modifying the arc into a high-temperature oven, carbon black is converted into carbon nanotubes by a solid-state transformation without a catalyst. This process sheds new light onto the growth mechanism of carbon nanotubes and could lead to a scalable method of making multiwall nanotubes.