Unveiling the mystery of nucleation and growth of carbon nanotube and layered graphene inside carbon arc-discharge

Abstract

A model for the formation of carbon nanotubes (CNTs) and layered graphene in an arc discharge method is developed on the basis of observed erosion of graphite anode under various experimental conditions and analyses of the morphology of the eroded anode-surface, concerned cathode deposits and their constituents. It is predicted that, cold thermal shock, triggered by the rapid movement of the anode-spot, leads to crack microbranching at some selected locations on the anode-surface. These crack-microbranches cleave and fragment the basal planes of pairs of adjacent crystallites into curved graphitic nanoribbons with minimum two basal planes. These nanoribbons further react chemically with the C2 and C3 precursors present in the dusty carbon plasma and evolve either in the form of CNT or layered-graphene, depending on the viscosity and composition of the gaseous environment they are exposed to, just after getting detached from the anode.