Unraveling the Charge State of Oxygen Vacancies in ZrO2–x on the Basis of Synergistic Computational and Experimental Evidence
| Autor: | Gerardino D'Errico, Luca De Stefano, Filomena Sannino, Ilaria Rea, Chiara Ricca, Antonio Aronne, Claudio Imparato, Ulrich Aschauer, Marzia Fantauzzi, Antonella Rossi, Cristiana Passiu |
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| Přispěvatelé: | Imparato, C., Fantauzzi, M., Passiu, C., Rea, I., Ricca, C., Aschauer, U., Sannino, F., D’Errico, G., De Stefano, L., Rossi, A., Aronne, A. |
| Rok vydání: | 2019 |
| Předmět: |
Materials science
Photoluminescence Diffuse reflectance infrared fourier transform 530 Physics Band gap Population Oxide 02 engineering and technology 010402 general chemistry 01 natural sciences law.invention chemistry.chemical_compound law 540 Chemistry Physical and Theoretical Chemistry Electron paramagnetic resonance education education.field_of_study Doping 021001 nanoscience & nanotechnology 0104 chemical sciences Surfaces Coatings and Films Electronic Optical and Magnetic Materials General Energy chemistry Chemical physics 0210 nano-technology Visible spectrum |
| Zdroj: | The Journal of Physical Chemistry C. 123:11581-11590 |
| ISSN: | 1932-7455 1932-7447 |
| Popis: | The functional properties of metal oxide semiconductors depend on intrinsic and extrinsic defects. The population of intrinsic defects is strongly affected by the synthesis method and subsequent treatments of the material, while extrinsic defects can originate from suitable doping. Stoichiometric ZrO2 is a nonreducible oxide with a large band gap. Therefore, controlling and modulating its defect profile to induce energy states in the band gap is the sole possibility to make it a photocatalyst responsive to visible light. We report a method, based on low temperature sol−gel synthesis coupled with treatments performed in mild conditions, to obtain undoped visible light-responsive ZrO2−x. The electronic structure of these materials is interpreted in relation to their oxygen vacancy defect population. On the basis of a wide set of experimental measurements (X-ray photoelectron, steady-state and time-resolved photoluminescence, electron paramagnetic resonance, and UV−visible diffuse reflectance spectroscopy) and supported by density functional theory calculations, we demonstrate, for the first time, the predominance of positively charged F-center oxygen vacancies that do not give rise to Zr3+ species. |
| Databáze: | OpenAIRE |
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