Synthesis and Characterization of Ultrathin Ceria Nanoplates Decorated with Transition Metal Ions

It is well known that nanoparticles properties can be easily tuned by changing the surface characteristics, which play an important role in determining many of the nanomaterials properties. In this work, ceria nanoparticles were modified by decoration of their surface with various transition metal ions. UV-Vis absorption, zeta potential, XPS and EDS measurements confirmed the attachment of the cation to the surface of ceria, both in solid state and in colloidal suspension. The metallization process was shown to have a significant effect on the optical properties and the surface charge of the nanoparticles, by forming an absorption peak in the visible region and consistently shifting the zeta potential to more positive values. We present for the first time zeta potential measurements of nanocrystals in an organic solvent, while in combination with other complementary methods it sheds some light on the actual behavior of the particles in suspension.