Synthesis And Morphology Control Of Nano-cerium Oxide And Cerium Oxide

The properties of rare earth nanomaterials are closely related to their morphology,size,phase,dispersivity and specific surface.In this article,the preparation of nano-rare earth oxides and new methods of morphology control have been studied.The nano-Y2O3 was prepared from YCl3 by the citrate precipitation method.The effects of reaction temperature,precursor concentration,hydrochloric acid concentration,surfactant,and calcination temperature on the mean sizes of nano-Y2O3 were studied.Several typical analytic techniques such as particle size analyzer,XRD,TG-DTA and SEM were used to exam the characteristics of nano powders.It was found that the highest yield is about 70% at the pH value of 5.0,the yield decreases rapidly at the pH value below 4 or over 6,the reaction temperature had no effect on the size of precursor.The optimized precursor concentration and hydrochloric acid concentration were both 0.1mol/L.Homogeneous torispherical nano-Y2O3 with the smallest size(20 nm)can be obtained by calcining the precursor powders at 800? for an hour,which were prepared by optimized precursor concentration and hydrochloric acid concentration in the presence of 1% surfactant PEG2000 and dried via an ethanol azeotropic distillation method.monodisperse neodymia(Nd2O3)nanoparticles with various shapes were synthesized easily by changing the concentration of N-(3-Cocoamidopropyl)-betaine(CAPB)ionic liquids surfactant,the morphology of product was highly influenced by the added amount of CAPB ionic liquids surfactant.With the increase of CAPB concentration from 0 to 20 times of critical micelle concentration(CMC),the morphologies of Nd2O3 varied from short nanorods,nanoballs,irregular flakes,highly regular leaf-shaped to torispherical nanoparticles.Forming mechanism of nanoparticles with various morphologies can be attributed to the different micelle structures,i.e.,sphere micelle,lamellar micelle and liquid crystal micelle,as the liquid templates for the precipitation reaction.The synthetic procedure is fairly simple and shows great promise for further extending the other ionic liquid(IL)surfactants to prepare nanoparticles and fabricates a variety of building blocks for assembling nanomaterials with novel structures and functionalities.