Control of morphology and dopant distribution in yttrium-doped ceria nanoparticles

The morphology and distribution of dopant in yttrium-doped ceria (YDC) nanoparticles prepared by spray pyrolysis were characterised by transmission electron microscopy and X-ray energy dispersive spectroscopy (XEDS), respectively. By combining the XEDS analysis and concentration distribution modelling, accurate yttrium dopant concentration variation from the particle center to the surface can be determined. It is shown that by appropriately selecting cerium precursors, the yttrium dopant distribution in YDC nanoparticles can be controlled. Uniform yttrium distribution in the YDC particles has been achieved, which is important to decrease probability of yttrium cluster segregation to improve oxygen ion conductivity in solid oxide fuel cell electrolytes. This control is based on the suggested mechanism of dopant distribution which proposes that hydration energies influence diffusion rates of the precursors during preparation process. In addition, the morphology (solid spherical, hollow spherical and hollow concave) formation mechanisms of the YDC particles from different cerium precursors are discussed.