Inhomogeneous depletion of oxygen ions in metal oxide nanoparticles
| Autor: | Andrey E. Davletshin, Anatoly I. Medvedev, I. V. Beketov, V. B. Vykhodets, Travis Whyte, S. I. Obukhov, Tatiana Eugenievna Kurennykh, Emily A. A. Jarvis, O. M. Samatov |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Zirconium
Materials science Inorganic chemistry Oxide chemistry.chemical_element Nanoparticle 02 engineering and technology Surfaces and Interfaces 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Oxygen Surfaces Coatings and Films Catalysis chemistry.chemical_compound chemistry 0103 physical sciences Materials Chemistry Cubic zirconia 010306 general physics 0210 nano-technology Yttria-stabilized zirconia Stoichiometry |
| Zdroj: | Surface Science. 644:141-147 |
| ISSN: | 0039-6028 |
| Popis: | Zirconia and yttria stabilized zirconia (YSZ) have multiple uses, including catalysis, fuel cells, dental applications, and thermal coatings. We employ nuclear reaction analysis to determine elemental composition of YSZ nanoparticles synthesized by laser evaporation including 18O studies to distinguish between oxide and adsorbed oxygen content as a function of surface area. We see dramatic deviation from stoichiometry that can be traced to loss of oxygen from the oxide near the surface of these nanopowders. Density functional calculations are coupled with these experimental studies to explore the electronic structure of nonstoichiometric surfaces achieved through depletion of oxygen. Our results show oxygen-depleted surfaces present under oxygen potentials where stoichiometric, oxygen-terminated surfaces would be favored thermodynamically for crystalline systems. Oxygen depletion at nanopowder surfaces can create effective two-dimensional surface metallic states while maintaining stoichiometry in the underlying nanoparticle core. This insight into nanopowder surfaces applies to dissimilar oxides of aluminum and zirconium indicating synthesis conditions may be more influential than the inherent oxide properties and displaying need for distinct models for nanopowders of these important engineering materials where surface chemistry dominates performance. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect