Carbon particles of variable shape produced by the chlorination of bis(benzene)chromium

Carbon particles with variable shape made of graphene-like layers have been obtained via chlorination of bis(benzene)chromium (Cr(C6H6)2) at two reaction temperatures. Their morphology and micro–nanostructure have been studied. At 400 °C sea urchin-like particles were detected, while at 900 °C cross linked pseudotubes, hollow and solid spheres were observed. Conventional transmission electron microscopy and high-resolution-TEM observations allow to determine that their structure is made of highly disordered graphene-like layers. The Raman spectrum of the high temperature sample exhibits the characteristics D and G bands. The peak positions, the ratio of their intensities (ID/IG) and full width at half maximum suggest a high degree of disorder in the nanostructures. The calculated in-plane correlation length of these graphene-like layers is 1.26 nm. In all the carbon particles, electron energy-loss spectroscopy shows a similar sp2 carbon bonding content (∼95%) and mass density in the range of 1.2–1.8 g/cm3. Textural studies show Type II adsorption isotherms with surface area of 1761 ± 29 m2/g for the sample produced at 900 °C, which is a high purity carbon sample.