The production of carbon particles of different shapes produced by the chlorination of Cr(C5H5)2

Abstract

Carbon particles have been obtained by the chlorination of chromocene (Cr(C5H5)2). Changes in their morphology and micro-nanostructure have been monitored at two different temperatures. At 400 C, filled materials (tubes and spheres) and agglomerated round particles are formed, whereas at 900 C closed-end tubes, hollow and solid spheres were produced. Transmission electron microscopy shows that these particles are formed of highly disordered graphene-like layers, which is confirmed by the absence of the 2D and 2G bands in the Raman spectrum. The calculated in-plane correlation length of these graphene-like layers is 1.2 ± 0.1 nm. In all the carbon particles, electron energy-loss spectroscopy shows a very similar sp2 carbon bonding content (89–98%) and mass density ranging from 1.6 to 1.8 g/cm3, both below standard graphite. Textural studies performed on the sample prepared at 900 C show Type II adsorption isotherms with a surface area of 694m2/g.