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 ~150 to ~250 nm, then 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.