Abstract
Arc discharge between graphite electrodes in cold liquid can give an ideal environment to emit vaporized carbon clusters and to achieve rapid quenching of these carbons into nano-cale structures. Carbon nanotubes, single-walled nanohorns, and metal-hybridized materials can be fabricated by such submerged arc discharge in water or liquid nitrogen. This method is superior to the conventional arc-in-gas method because the present method does not require any expensive vacuum facilities. The selectivity of the products depends on the condition of the reaction field in the arc-in-liquid system, for example, discharge current density, liquid components, and doping concentration of additives in anode. It was suggested that the relatively inert environment at the arc plasma zone is essential to produce the single-walled structures. To realize such condition in water, the arc-in-water method with gas injection was demonstrated.
