Facile synthesis of ceria nanospheres by Ce(OH)CO₃ precursors

Spherical Ce(OH)CO₃ precursors were prepared via a facile and an efficient hydrothermal process without hard templates. X-ray diffraction (XRD) analysis reveals that the as-synthesized spherical precursors are composed of high-purity Ce(OH)CO₃ with a hexagonal structure. After calcination at 573 K for 10 h, the spherical Ce(OH)CO₃ precursors decompose into CeO₂ nanospheres with a cubic fluorite structure. We also find that morphology of the Ce(OH)CO₃ precursors and CeO₂ nanospheres is modified significantly as a function of the different surfactants used in the hydrothermal process. When using PEG surfactant, the Ce(OH)CO ₃ precursors and CeO₂ nanospheres turn compact with wrinkles on surface, while they appear like nanospheres formed by aggregated nanoparticles when the PVP surfactant is used. The CeO₂ nanospheres prepared by both surfactants exhibit excellent ultraviolet shelter ability and hold promise for a wide range of technological applications.