Synthesis of VC nanopowders by thermal processing of precursor with CaF2 addition

Vanadium carbide (V8C7) nanopowders were synthesized by thermal processing the precursor of NH4VO3 and nanometer carbon black with about 1 wt% CaF2 addition. The reaction process, phase composite, microstructure and element binding state of V8C7 were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET) techniques and X-ray photoelectron spectroscopy (XPS). The results showed that with CaF2 addition, single phase V8C7 powders can be successfully obtained at 950 oC for 1 h, which is 150-500 oC lower than those of conventional synthesis methods. The product exhibited the morphology of spheroid and consists of multiple particles 40 nm in size. The specific surface area, average pore size and measured pore volume of the sample are 63.36 m2 g-1, 3.56 nm and 0.23 cm3 g-1, respectively.