Transmission electron microscopy characterization of nanostructured carbon derived from Cr3C2 and Cr(C5H7O2)3

The preparation, characterization and comparison of nanostructured carbons derived by direct chlorination of Cr3C2 and Cr(C5H7O2)3 are reported in this work. Cr3C2 precursor was treated at 400 and 900 °C with a reaction time of 1 h. The nanostructure of the products has been characterized in some detail by means of transmission electron microscopy and associated techniques, such as electron energy-loss and X-ray energy dispersive spectroscopies and high-angle annular dark field imaging. Remains of Cr3C2 encapsulated in an amorphous carbon shell were observed at 400 °C, whereas carbon with higher ordering degree was produced at 900 °C. In the latter case, the sample can be described as a continuous variation from poorly-stacked graphene-like carbon to graphitic agglomerates. Remains of the reaction by-product, CrCl3, are detected in the carbon particles, forming monolayers intercalated inside the graphitic agglomerates and amorphous nanoparticles. As a comparison, carbon samples derived from Cr(C5H7O2)3 were prepared at 300 and 900 °C. They mainly consist of highly disordered carbon, with local graphite-like stacking in the sample prepared at 900 °C.