Synthesis and Characterization of Cerium Dioxide Nanoparticles Obtained by a Novel Soft Mechanochemical Method Combined with Sol-Gel Method.

After mechanochemical reaction of hydrous cerium (III) chloride and citric acid with a little of ethanol followed by a subsequent calcination process at different temperature, cerium dioxide nanoparticles with fluorite structure were successfully prepared. Then the obtained ceria powders were characterized by means of X-ray diffractometer, specific surface area analyzer, scanning electron microscope, transmission electron microscopy and laser particle analyzer. It was found that the degree of particle aggregation passed through a minimum with the calcination temperature rising from 400C to 800C, accompanied with growth of particle size. The ceria powders calcined at 500C had an average aggregated particle size of 59.8nm with uniform spheroidal morphology, while their crystallite sizes ranged from 10nm to 20nm. Yet the product calcined at 400C had the maximum specific surface area of 109.6m2/g. In polishing experiment, the ceria powders calcined at 500C showed great polishing performances. CeO2 nanoparticles with spheroidal morphology were successfully prepared via a novel soft mechanochemical method, combined with the sol-gel method. The viscous gel originated from mechanochemical treatment and the later xerogel, after drying, could greatly inhibit the aggregation and growth of the particles. The particle size and dispersity of the product could be controlled by changing the calcination temperature. This novel synthesis route was very suitable for large-scale industrial production. [ABSTRACT FROM AUTHOR]