Study on the preparation of V(N, O) powder by reduction of V₂O₅ with ammonia at low temperatures

Vanadium nitride is successfully prepared via the reduction of V₂O₅ in ammonia atmosphere in the temperature range of 773 K to 873 K. Phase transitions and morphology evolutions during the reduction of V₂O₅ to VN were analyzed by X-ray diffraction (XRD) and Field-emission scanning electron microscope (FE-SEM), respectively. Thermal Gravity Analysis (TGA), X-ray photoelectron spectroscopy (XPS), chemical analysis and Brunauer Emmett Teller (BET) were used to material characterizations. According to the results of XRD, XPS and chemical analysis, the final products should be V(N, O) and the reaction sequence of V₂O₅ with ammonia from 773 K to 873 K was: V₂O₅→VO₂→V₄O₇→V₂O₃→V(O, N). Regarding the morphology evolutions during the ammonia reduction process, the size and shape of VN particle were almost kept the same as that of V₂O₅, except that one VN particle were composed of many small VN grains.