Synthesis of CeO₂, ZrO₂ nanocrystals, and core-shell-type nanocomposites

The synthesis of Ce O2 Zr O2 core-shell nanocrystals (NCs), which are Ce O2 NCs overcoated by a thin Zr O2 layer, has been studied together with Ce O2 and Zr O2 NCs using a hot surfactant colloidal route. Colloidal solutions in oleylamine of the Ce O2 NCs with a 2.0-2.5 nm diameter and Zr O2 NCs with a 2.5-3.5 nm diameter were, respectively, synthesized by the thermolysis of Ce (acac)3 and the reaction of Zr [OCH (C H3) 2] 4 and Zr Cl4. The Ce O2 Zr O2 core-shell NCs have been successfully synthesized by the addition of Ce O2 NCs as seed crystals in the Zr O2 source solution and its reaction at 300°C. The core-shell nanostructure, which consists of a 2.4 nm diameter Ce O2 core and 1.2 nm thick Zr O2 shell, was supported by its X-ray diffraction, high-resolution transmission electron microscopy, and X-ray photoelectron spectroscopy results.The Electrochemical Society