Electrochemical Stability of the Reconstructed Fe<sub>3</sub>O<sub>4</sub>(001) Surface
Establishing the atomic-scale structure of metal-oxide surfaces during electrochemical reactions is a key step to modeling this important class of electrocatalysts. Here, we demonstrate that the characteristic (√2×√2)R45° surface reconstruction formed on (001)-oriented magnetite single crystals is m...
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| Autores principales: | , , , , , , , , , , |
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| Formato: | Articulo Comunicacion |
| Lenguaje: | Inglés |
| Publicado: |
2020
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| Materias: | |
| Acceso en línea: | http://sedici.unlp.edu.ar/handle/10915/127248 https://onlinelibrary.wiley.com/doi/10.1002/anie.202008785?__cf_chl_jschl_tk__=pmd_NJBLsJFYqAW_KRAEx01KFcpGyi6cJIU5hZ4O7RUljFQ-1635251321-0-gqNtZGzNAiWjcnBszQkR |
| Aporte de: |
| Sumario: | Establishing the atomic-scale structure of metal-oxide surfaces during electrochemical reactions is a key step to modeling this important class of electrocatalysts. Here, we demonstrate that the characteristic (√2×√2)R45° surface reconstruction formed on (001)-oriented magnetite single crystals is maintained after immersion in 0.1 M NaOH at 0.20 V vs. Ag/AgCl and we investigate its dependence on the electrode potential. We follow the evolution of the surface using in situ and operando surface X-ray diffraction from the onset of hydrogen evolution, to potentials deep in the oxygen evolution reaction (OER) regime. The reconstruction remains stable for hours between -0.20 and 0.60 V and, surprisingly, is still present at anodic current densities of up to 10 mA cm-2 and strongly affects the OER kinetics. We attribute this to a stabilization of the F<sub>3</sub>O<sub>4</sub> bulk by the reconstructed surface. At more negative potentials, a gradual and largely irreversible lifting of the reconstruction is observed due to the onset of oxide reduction. |
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