Controlled hydrothermal synthesis, excellent optical and magnetic properties of CeO2 nanocubes

The CeO2 nanocubes with rough surface have been successfully synthesized by a facile hydrothermal technique. The reaction temperature was systematically investigated. X-ray diffractometer, scanning electron microscope, transmission electron microscope, X-ray photoelectron spectroscopy, Raman scattering, ultraviolet-visible and Photoluminescence spectra, and magnetization hysteresis (M-H) curves were employed to characterize the samples. The results showed that all the CeO2 nanocubes owned a fluorite cubic structure and there are Ce3+ ions and oxygen vacancies in surface of samples. Although the morphology had a slight difference for the samples synthesized at different temperature and the average edge length of the nanocubes increased from similar to 150 to similar to 250 nm, then to similar to 350 nm with the enhancement of temperature, the cube-like morphology remained unchanged. The synthesized CeO2 samples show excellent room temperature optical properties. The M-H curves of CeO2 nano-octahedrons exhibit excellent room-temperature ferromagnetism, which is likely attributed to the effects of the different morphology of samples, Ce3+ ions and oxygen vacancies.