Preparation Of Vanadium Nitride By Gel Method

With the development of the iron and steel industry and the electronics industry, the application of vanadium nitride is more and more widely. The traditional preparation methods of vanadium nitride had a disadvantage of high energy consumption, low product purity. In this experiment, vanadium pentoxide powder and ammonia were used as raw materials, and vanadium nitride was prepared by gel method. Mainly studied the melting temperature, holding time, mass ratio of H2O/V2O5, nitriding temperature, gas flow rate and nitriding time factors on nitriding rate influence.The vanadium nitride products were characterized by XRD and SEM.Research shows that when the melting temperature 800℃, the holding time 10 min, the mass ratio of H2O/V2O5 33, the nitriding temperature 750℃, the ammonia gas flow rate 80 m L/min and the nitriding time 14 h, the nitriding rate can be 95%. With increasing temperature, the nitrogen content of vanadium nitride and nitriding rate increases gradually. The XRD analysis showed that the purity of the product is high, the average grain size of 100 nm. the mass ratio of H2O/V2O5 on the quality of the dried gel prepared than most, followed by melting temperature and time.Thermodynamic studies show that the reduction nitriding process, due to the decomposition of ammonia, V2O5 is first reduced to V2O3, subsequently reduced to ammonia VN.(NH4)2V3O8 substance appear in the reduction nitriding process and decomposition at 850℃. The isothermal Kinetic studies show that: the reaction of V2O3 reduction with VN is consistent with the random nucleation and subsequent growth model, the reaction order is 1, the activation energy is 29.2KJ/mol, the frequency factor is 172.43 min-1, the rate constant k is 4.5 × 10-3min-1.The electrochemical properties of vanadium nitride were tested.The test results showed that the cyclic voltammetry curve close to rectangular, the constant current charge / discharge curve symmetry is good and the charge transfer resistance is low, showed that vanadium nitride electrode surface in the presence of rapidly reversible electrochemical reaction and suitable for the electrode material of the capacitor.