Graphitic cones in carbon nanofibres

High yields of graphitic conical nanofibres (5-70 nm OD; <5 µm in length) are produced by pyrolysing various palladium precursors under an Ar atmosphere at 850-1000°C. The fibres exhibit diamond-shaped Pd particles at their tips, which are responsible for the carbon aggregation and its subsequent diffusion. This carbon replication phenomenon on the Pd particles results in the formation of stacked graphene cones, which grow aligned along a common axis, thus creating graphitic nanofibres. The cones within the fibres can be either open (lamp-shade type) or closed. The material has been analysed using sophisticated electron microscopy (HRTEM, SEM, ED) and spectroscopic techniques (Raman, EELS, EDX). Due to the large number of open edges, we envisage that these novel nanofibres may find important applications in the fabrication of field emitters, gas storage devices and composites.