Synthesis and characterization of cerium oxide nanoparticles using different solvents for electrochemical applications

Cerium oxide nanoparticles were synthesized through sol–gel method using different solvents which include water, acetone, ethanol and ethylene glycol. Cerium (III) nitrate hexahydrate and ammonium hydroxide were used as the precursors. The influence of the solvent on the structural, optical and electrochemical properties was investigated using powder X-ray diffraction, transmission electron microscope imaging, selected area electron diffraction (SAED), Fourier transform infrared spectroscopy (FTIR), UV–visible absorption spectroscopy, photoluminescence (PL) spectroscopy, cyclic voltammetry (CV) measurement and galvanostatic charge–discharge analysis. A significant change in the properties of the samples was observed in all the characterization techniques, and it was well discussed with the already reported data. Especially with the help of electrochemical studies, it was found that ethylene glycol used as a solvent can easily activate the surface defects in the crystal structure rather than other solvents. This may be due to the fact that the nanocrystalline cerium oxide contains interchangeable oxidation states (Ce4+ and Ce3+) resulting from the oxygen vacancy. The atmospheric molecular oxygen can easily react with these surface oxygen vacancies and forms highly active atomic oxygen over the surface of the material which enhances the electrochemical property of the material. The results of the present study provide a promising platform for developing a cathode material for electrochemical applications.