Carbon nanotube synthesis by arc discharge in water using metal cathodes

Abstract

Carbon nanotube (CNT) synthesis by arc discharge in water can yield high-crystallinity CNTs using simple equipment. However, it is difficult to control the morphology of CNTs, such as their length, diameter, and number of layers, because the mechanism of CNT production by arc discharge method is complicated. We describe how the morphology of CNTs depends on the cathode metal used in arc discharge. When a nickel or tungsten cathode was used, the layer number distribution was narrower than when a graphite electrode was used. Additionally, the peak position of the inner diameter distribution was downshifted in the case of tungsten. The downshift is considered to be caused by the presence of tungsten nanoparticles as a catalyst. © 2010 The Surface Science Society of Japan.