Synthesis of high‐quality vanadium nitride particles by one‐step vacuum carbothermal reduction–nitridation method: Theoretical and experimental study

Abstract

AbstractOwing to its high hardness, favorable stability, and good electrical performance, vanadium nitride (VN) has been extensively used as an alloy additive, an electrode material, a ceramic material, and a catalyst. However, traditional VN synthesis methods require high temperatures and long soaking times. In this study, high‐quality VN particles were prepared from V2O3 powder at a lower temperature and shorter soaking time by a one‐step vacuum carbothermal reduction–nitridation (VCRN) method. Thermodynamic and kinetic analyses elucidated the mechanism of this process. Thermodynamic analysis showed that vacuum was conducive to the carbothermal reduction of V2O3, reducing the initial reaction temperature, and the main reaction path was V2O3→VO→VxCy(VC/ V2C/ V8C7/ V6C5)→VN. Kinetic results indicated that the one‐step VCRN method was a gas–solid reaction. Within the temperature range of 1373–1473 K, the rate‐determining step was controlled by the carbothermal reduction–nitridation reaction, combination control of the reduction–nitridation reaction and the interlayer diffusion, and interlayer diffusion control of N2 during the different reaction processes. High‐quality VN particles obtained at a temperature of 1473 K, pressure of 300 Pa, and soaking time of 3 h were characterized by X‐ray diffraction, transmission electron microscopy, energy dispersive X‐ray spectroscopy, and particle size distributions. The O and N contents, measured by an O/N analyzer, were 0.85% and 19%, respectively, and the C content, measured by a C/S analyzer, was 0.92%. These analyses indicate that high‐quality VN can be obtained by a one‐step VCRN method.