Preparation and characterization of size-controlled CeO2 nanoparticles coated with SiO2

CeO2@SiO2 (core@shell) nanoparticles were prepared by means of chemical precipitation technique. Results from X-ray diffraction, transmission electron microscopy (TEM), and Zeta-potential analyses provide strong microscopic and spectroscopic evidences to prove that CeO2 particles have been encapsulated inside amorphous SiO2 shell. As revealed from TEM investigations, the average grain size of CeO2@SiO2 is significantly smaller than that of uncoated CeO2 nanoparticles prepared under the same conditions, indicating it is an effective method to restrict the grain enlargement of nanocrystalline CeO2 by coating a thin layer of SiO2 at elevated temperatures. The CeO2@SiO2 nanoparticles display a similar surface electric character behavior to that of SiO2, and its dispersibility in water is improved.