Preparation of niobium nanoparticles by sodiothermic reduction of Nb ₂ O ₅ in molten salts

Abstract

Abstract Niobium nanoparticles with high purity were prepared by a sodiothermic reduction process using Nb 2 O 5 as the raw material, LiCl, NaCl, KCl and CaCl 2 as the diluents and sodium as the reducing reagent. The effects of the different molten salt systems, CaCl 2 content, reaction time, excessive sodium and reaction temperature on the characteristics of the obtained niobium powder were discussed. The as‐prepared niobium nanoparticles under the optimum experimental conditions were obtained by sodiothermic reduction with 20% excessive sodium in the NaCl‐52mol%CaCl 2 ‐2mol%Nb 2 O 5 molten salts at 650 °C for 6 h, and the molar ratio of the oxygen element in Nb 2 O 5 and the CaCl 2 of the molten salts is less than 19.23% at 750 °C. Moreover, the particle size of niobium nanoparticles is ranged about 40∼240 nm with increasing of reaction temperature from 650 to 800 °C.