Highly uniform Ce(OH)CO3 flowers were successfully prepared in large quantities using a facile hydrothermal approach from the reaction of Ce(NH4)(NO3)4 with CO(NH2)2 at 160 ℃ in a water-N 2H4 complex.The influences of the N2H4 content and temperature on flower formation were discussed.CeO2 flowers were prepared by thermal conversion of Ce(OH)CO3 flowers at 500℃ in air.Both Ce(OH)CO3 and CeO2 flowers were characterized by X-ray powder diffraction(XRD),and scanning electron microscopy(SEM).The UV-vis adsorption spectrum of the CeO2 flowers showed that the band gap energy(Eg) is 2.66 eV,which is lower than that of bulk ceria.
