Low-Temperature Synthesis of VB2 Nanopowders by a Molten-Salt-Assisted Borothermal Reduction Process
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Vanadium diboride (VB2) powders with low oxygen content are prepared via a molten-salt-assisted borothermal reduction reaction at 1123 K to 1273 K (850 °C to 1000 °C) using V2O3 and boron powders as the raw materials. The effects of the amount of molten salt and reaction temperature on the phase transition and morphology of the final products are investigated. The results reveal that the addition of molten salt is beneficial for decreasing both the synthesis temperature and particle size of the final products. When the mass ratio of NaCl to reactants is 0.75:1, the VB2 powders prepared at 1173 K (900 °C) have a particle size lower than 100 nm. Too little or too high molten salt addition has a negative impact on the preparation of the VB2 powders. Furthermore, the reaction temperature has an important impact on the morphology and purity of the VB2 particles. An appropriate reaction temperature (1173 K (900 °C)) is beneficial for controlling the size of the VB2 particles in the order of nanoscale and improving the quality of the VB2 powders.
This work was supported by the Fundamental Research Funds for the Central Universities (FRF-GF-17-B41).
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