Preparation of Graphene Materials through Pulsed Wire Discharge*

Graphene is a two-dimensional structure of carbon atoms packed into a honeycomb lattice, which is known as the thinnest material thus far. The graphene materials feature multiple properties and have been used in various applications. Pulsed wire discharge refers to a series phenomena induced by a huge energy input in a conductive wire using pulsed discharge. Once the current passes through the wire, it melts and vaporizes in microseconds to produce a mixture of droplets and vapors at high temperature and pressure. The products scatter out with a shockwave in medium and cools down to form nanoparticles subsequently. In this study, graphene materials were produced using graphite stick and graphite wire via pulsed wire discharge in distilled water. The as-prepared samples were characterized by various techniques to confirm the formation of graphene materials. In this method, delicate control of energy input is critical for graphene formation. The graphitic layers were exfoliated from graphite materials by thermal expansion effect. On the basis of pulsed wire discahrge, the corresponding mechanisms that governs the graphene generation were carefully illustrated.