Vanadium nitride (VN) plays an important role in high-strength steel production due to the unique precipitation strengthening and grain refinement effects [1]. high-purity VN is widely used in the fields of advanced materials, batteries and catalysts since high electrical conductivity, high thermal conductivity and good chemical stability [2, 3]. The traditional method for preparing VN is the carbon thermal reduction method [4]. Nowadays, thermal processing precursor method is highly anticipated for preparing high-quality VN due to lower reaction temperature, simple process, and short production process [5]. This method includes two steps, which the precursors containing the shell of vanadium and core of carbon powders are formed and then the precursors are reduced and nitrided in the N2 atmosphere to obtain VN.
However, carbon powders are difficult to disperse in the solution uniformly owing to the huge surface tension and adsorption properties, and the precursors prepared subsequently are agglomerate. This is the main reason that the reaction is insufficient during the nitrogen reduction process, which affects the quality of VN.
In response to the above issue, Polyvinyl pyrrolidone (PVP) and the other two dispersants are used to optimize the structure of the precursors in order to prepare high quality VN. Under optimum condition of 1150 °C, the VN with nitrogen content of 17.94% is prepared by adding 5% PVP. When the reaction temperature exceeds 400 °C, the precursors of adding 5% PVP are easily converted to V7O13, V3O5, V2O3 and VN at the same temperature. The precursors of adding 5% PVP have lower Ea during reduction and nitration process, which are easier to be reduced and nitridated. In comparison with the process without adding dispersants, the addition of carbon powders is reduced by 9% and the nitriding time is decreased by 75%, which reduce CO2 emission, the energy consumption for generation and the production cost.