Morphology-Tuneable Synthesis and Magnetic Performances of CeO 2 Hollow Nanospheres Fabricated by a Simple Template-Free Hydrothermal Method

The large-scale uniform CeO2 hollow nanospheres with a diameter of about 200–300 nm were fabricated by a facile template-free hydrothermal method using Ce(NO3)3 ⋅6H2O as cerium source, NH4HCO3 as precipitator, and ethanediamine as surfactant. X-ray diffraction (XRD), X-ray photoelectron spectrum (XPS), and Raman spectrum showed that the CeO2 hollow nanospheres with no crystalline impurity phase have a cubic fluorite structure, and many Ce3+ ions and oxygen vacancies exist in its surface. The magnetic measurements show that the CeO2 hollow nanospheres have excellent room temperature ferromagnetism while its precursors exhibit paramagnetism The dominating influences on RTFM may be assigned to the morphology and size of obtained CeO2 samples.