Preparation of CuNb2O6 nanocrystalline powders by sol-gel method

The soluble solution with Nb5+ was obtained by dissolving Nb2O5 into HF acid, and CuNb2O6 nanocrystalline powders were synthesized using this soluble solution as starting materials at a low temperature by sol-gel method in this study. The crystal structure and microstructure of CuNb2O6 powders were characterized by XRD and SEM techniques, and the effects of pH value and the molar ratio of citric acid to the niobium ions (CA/Nb) on the crystal structure and microstructure of CuNb2O6 powders were also investigated. XRD and TG/DTA results show that the monoclinic phase of CuNb2O6 for synthesized powders can be obtained by calcining the precursor at 600 deg. C. The average particle size of CuNb2O6 ranges from 20 nm to 85 nm with varying the CA/Nb and pH values, and 20 nm of the particle size can be obtained for the CuNb2O6 powders by heating the precursor at 600 deg. C for 2 h.