Ultra-thin cerium oxide nanostructures through a facile aqueous synthetic strategy

摘要

In this work, synthesis of ultra-thin 2D CeO_2 nanoribbons is reported for the first time along with rod-shaped nanostructures via a surfactant free aqueous method. CeO_2 nanoribbons of length > 100 nm have been synthesised through a mild reaction route involving ammonia precipitation and subsequent heating and ageing at 0 °C. 2D nanostructures are proposed to be formed as a result of self-assembly of CeO_2 molecules. The ribbons exhibited amorphous X-ray diffraction pattern and TEM showed a ribbon like morphology with crystal facets of ～0.33 nm spacing corresponding to (1 1 1) plane of CeO_2. HR-TEM confirmed that the nanorods are enclosed by {1 1 1} planes and have preferentially grown in {1 10} direction. The surface area of the powder containing majority nanorods is 82 m~2/g and their average pore size is ～3 nm. The nanostructures exhibited optical band gaps dominated by the regular quantum confinement effect as well as presence of defects.