Low temperature synthesis of chromium carbide (Cr3C2) nanopowders by a novel precursor method

• A novel precursor method was used to synthesize Cr3C2 nanopowders.
• (NH4)2Cr2O7 and C6H12O6 were used as raw materials.
• Single phase Cr3C2 nanopowders can be synthesized at 900 °C in 1 h.
• The synthesis temperature is at least 500 °C lower than that of conventional methods.
• The powders show good dispersion and consist of particles of about 30 nm.

Chromium carbide (Cr3C2) nanopowders have been synthesized by a novel solution-derived precursor method, and the raw materials are ammonium dichromate ((NH4)2Cr2O7) and glucose (C6H12O6). The products were characterized by X-ray diffractometry (XRD), thermogravimetric and differential scanning calorimetry (TG-DSC), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) techniques. The results show that Cr3C2 nanopowders with an average crystallite size of 32 nm can be synthesized at 900 °C in 1 h. The powders synthesized by this approach show good dispersion and are mainly composed of spherical or nearly spherical particles with a mean diameter of about 30 nm. The weight loss ratio of the precursor during the reaction is about 55 wt.%, and it reduces rapidly before 400 °C (about 45 wt.%). The surface of the specimen mainly consists of three elements, Cr, C and O. The XPS spectrum of Cr2p consists of two peaks with the binding energies of 575.8 eV and 577.4 eV, which are assigned to the Cr2p3/2 species of Cr3C2 -x (0 ≤ x ≤ 0.5) and Cr2O3, respectively.