Preparation of Polyhedral Graphite Particles by Arc Discharge under Atmospheric Pressure

Abstract

Polyhedral graphite particles (PGPs) were synthesized by arc discharge method under atmospheric pressure in the relatively short electrode gap distance of 1 mm, while graphene flakes and turbostratic graphite were found by increasing the electrode gap distance. The selective synthesis of nano-sized carbon allotropes was controlled by the contribution of carbon ions and carbon radicals with the change of the electrode gap distance. The formation mechanism of PGPs and other carbon allotropes were proposed according to the experimental results. The low concentration of carbon ions to carbon radicals contributes to the formation of PGPs. In contrast, relatively high concentration of carbon ions to carbon radicals contributes to the formation of graphene flakes and turbostratic graphite.