Controlled Hydrothermal Synthesis, Optical and Magnetic Properties of Monodisperse Leaf-Like CeO₂ Nanosheets.

The monodisperse leaf-like CeO2 nanosheets of about 40 nm in thickness have been successfully synthesized by a simple hydrothermal route. SEM, XRD, FT-IR, TG-DSC, XPS, Raman scattering, Photoluminescence (PL) spectra and M-H curves were employed to characterize the samples. The results showed that all the CeO2 samples had a cubic fluorite structure and there are Ce3+ ions and oxygen vacancies in the surface of samples. Based on the SEM patterns, a clear morphology transformation from leaf-like to heart-shaped, and then to triangular prism-like structure was observed. The magnetic and photoluminescence measurements displayed that all the samples have excellent ferromagnetism and optical properties at room temperature and the ferromagnetism and optical properties increase along with the rise of NH4HCO3 concentration, which can be reasonably explained for the affects of the morphology of samples, the concentration of oxygen vacancies and Ce3+ ions.