Synthesis of chromium carbide (Cr3C2) nanopowders by the carbonization of the precursor

The solution-derived precursor method was used to synthesize chromium carbide (Cr3C2) nanopowders, ammonium dichromate ((NH4)2Cr2O7) and nanometer carbon black were used as raw materials. The products were characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) techniques. The results show that the single phase Cr3C2 can be synthesized under the conditions of 21 wt.% C, 1100 °C and 30 min, and the average crystallite size is 27.2 nm. The powders show good dispersion and are mainly composed of spherical or near- spherical particles with a mean diameter of ~ 30 nm. The surface of the specimen mainly consists of Cr, C and O three species elements. The XPS spectrum of Cr2p consists of two peaks with the binding energies of 577.5 eV and 575.3 eV, which are assigned to the Cr2p3/2 species of Cr2O3 and Cr3C2 − x (0 ≤ x ≤ 0.5), respectively. The XPS spectrum of O1s energy region for chromium carbide contains three peaks (Oa, Oh and Od), which are considered to be due to O−, OH− and Cr2O3, respectively.

Research highlights
► The solution-derived precursor method was used to synthesize chromium carbide (Cr3C2) nanopowders.
► Ammonium dichromate ((NH4)2Cr2O7) and nanometer carbon black were used as raw materials.
► Single phase Cr3C2 nanopowders can be synthesized at 1100 °C and 0.5 h.
► The powders show good dispersion and are mainly composed of particles with a mean diameter of ~ 30 nm.