Synthesis of doped ceria–zirconia core–shell nanocomposites via sol–gel process

In order to introduce more conductive interfaces, the doped ceria–zirconia core–shell nanocomposites are synthesized via a simple and low-cost sol–gel process. Nitrates, citric acid and polyethylene glycol (PEG) are used as starting materials, and the compositions of the core and the shell are Ce0.9Gd0.1O1.95 (GDC) and 8 mol% Sc2O3 doped ZrO2 (ScDZ), respectively. The room-temperature ammonia co-precipitation method is used to prepare the core materials. X-ray diffraction (XRD) indicates that the average grain sizes of the core and shell materials are about 6 nm and 8 nm. The core–shell nanostructure with about 60 nm diameter GDC core (approximate) and about 20 nm thick ScDZ shell, is supported by the field-emission scanning electron microscopy (FESEM) and the transmission electron microscopy (TEM) results. The effects of PEG and the mechanisms during the process of forming the core–shell nanocomposites are discussed in detail.