Production of Carbon Nanotubes by an Underwater Arc Discharge Method Using a Metal Cathode

Carbon nanotubes (CNTs) are produced by an arc discharge method, using carbon for both electrodes along with a metal catalyst for the cathode. In this study, we conducted experiments using four kinds of metals (iron, copper, manganin, and nickel) for the cathode and investigated the difference in product and production yield due to the differences in the metals. The greatest quantity of high quality CNTs was produced with nickel as the metal catalyst, with some CNTs as large as 10 microns. Iron produced almost no CNTs, copper produced linear CNTs, and manganin produced a small quantity of very short CNTs.