Mechanistic Insight into the Precursor Chemistry of ZrO2 and HfO2 Nanocrystals; towards Size-Tunable Syntheses
| Autor: | Rohan Pokratath, Dietger Van den Eynden, Susan Rudd Cooper, Jette Katja Mathiesen, Valérie Waser, Mike Devereux, Simon J. L. Billinge, Markus Meuwly, Kirsten M. Ø. Jensen, Jonathan De Roo |
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| Rok vydání: | 2021 |
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| Zdroj: | Pokratath, R, Van Den Eynden, D, Cooper, S R, Mathiesen, J K, Waser, V, Devereux, M, Billinge, S J L, Meuwly, M, Jensen, K M Ø & De Roo, J 2022, ' Mechanistic Insight into the Precursor Chemistry of ZrO 2 and HfO 2 Nanocrystals; Towards Size-Tunable Syntheses ', Journal of the American Chemical Society, vol. 2, no. 4, pp. 827-838 . https://doi.org/10.1021/jacsau.1c00568 JACS Au 2(4), 827-838 (2022). doi:10.1021/jacsau.1c00568 |
| Popis: | JACS Au 2(4), 827 - 838 (2022). doi:10.1021/jacsau.1c00568 One can nowadays readily generate monodisperse colloidal nanocrystals, but a retrosynthetic analysis is still not possible since the underlying chemistry is often poorly understood. Here, we provide insight into the reaction mechanism of colloidal zirconia and hafnia nanocrystals synthesized from metal chloride and metal isopropoxide. We identify the active precursor species in the reaction mixture through a combination of nuclear magnetic resonance spectroscopy (NMR), density functional theory (DFT) calculations, and pair distribution function (PDF) analysis. We gain insight into the interaction of the surfactant, tri-n-octylphosphine oxide (TOPO), and the different precursors. Interestingly, we identify a peculiar X-type ligand redistribution mechanism that can be steered by the relative amount of Lewis base (L-type). We further monitor how the reaction mixture decomposes using solution NMR and gas chromatography, and we find that ZrCl4 is formed as a by-product of the reaction, limiting the reaction yield. The reaction proceeds via two competing mechanisms: E1 elimination (dominating) and SN1 substitution (minor). Using this new mechanistic insight, we adapted the synthesis to optimize the yield and gain control over nanocrystal size. These insights will allow the rational design and synthesis of complex oxide nanocrystals. Published by ACS Publications, Washington, DC |
| Databáze: | OpenAIRE |
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