Experimental Aspects for CeO2 Nanoparticles Synthesis and Characterization

Résumé

In recent years, cerium oxide (CeO₂, or ceria) became a versatile nanostructured material because of its unique properties derived from the low dimensionality and high surface area. It was also extensively studied due to its practical performances in many scientific and industrial applications, such as fuel cells, luminescent materials, gas sensors, insulators, white LEDs, etc.
In this paper, the research focused on the synthesis and characterization of cerium oxide powder manufactured by the co-precipitation method, using inorganic cerium salt (Ce(NO₃)₃) and the precipitating agent (NaOH). In order to optimize the CeO₂ particles synthesis process, the parameters of the process were monitored to obtain the quantitative precipitate and to optimize the heat treatment. The precursors type and concentration used, reaction temperature and time, the pH of reaction medium and order of the precipitating agent addition are the main factors influencing the particle size and morphology of cerium oxide nanoparticles.

The physico-chemical properties of the cerium oxide nanoparticles were determined by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX). The FTIR spectrum of the CeO₂ particles calcinated at 550 °C, in normal atmosphere, exhibits a strong band at 482 cm^-1 corresponding to Ce-O stretching vibration. The XRD pattern confirmed the crystalline nature of the CeO₂ nanoparticles with a cubic structure and average crystallite size around 15 nm. Moreover, EDX analysis confirms the presence of the Ce and O atoms corresponding to the theoretical formula. The morphology and microstructure were studied using SEM analysis.