Downstream analytics quantification of ion release during high-voltage anodisation of niobium
| Autor: | Achim Walter Hassel, Andrei Ionut Mardare, Cezarina Cela Mardare, Jan Philipp Kollender |
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| Rok vydání: | 2018 |
| Předmět: |
Materials science
Niobium Analytical chemistry Oxide chemistry.chemical_element 02 engineering and technology 010402 general chemistry Electrochemistry 01 natural sciences law.invention chemistry.chemical_compound law Valve metals General Materials Science Electrical and Electronic Engineering Crystallization Dissolution Horizontal scan rate Anodizing 021001 nanoscience & nanotechnology Condensed Matter Physics 0104 chemical sciences Amorphous solid Anodisation High-field regime Inductively coupled plasma mass spectrometry chemistry 0210 nano-technology |
| Zdroj: | Journal of Solid State Electrochemistry. 22:2457-2464 |
| ISSN: | 1433-0768 1432-8488 |
| DOI: | 10.1007/s10008-018-3957-4 |
| Popis: | In operando quantification of field-assisted ion release during high-voltage anodisation (up to 100 V SHE) of Nb in 0.1 M sulphuric acid was performed. Electrochemical high-field oxide formation under both potential and current control was studied separately. The quantification of in situ ion release via ICP-MS revealed an increase of the oxide dissolution factor (from 337 to 422 fm V−1) when decreasing the potential scan rate from 200 to 100 mV s−1. Dissolution rates measured during galvanostatic oxide formation allowed measuring oxide dissolution factors of 719 and 837 fm V−1 for current densities of 1.0 and 0.5 mA cm−2, respectively. As compared to the potentiodynamic case, higher dissolution rates and oxide dissolution factors were measured for galvanostatic anodisation. The overall fraction of the charge used for generation of soluble Nb species was below 0.4% for all oxide growth regimes. Cross-sectional SEM imaging proofs an oxide formation factor of 2.1 nm V−1. The surface of anodised films was extremely smooth and featureless without any cracks or voids. Based on X-ray diffraction, the films were found to be amorphous, indicating that no field crystallisation is occurring under the applied oxide growth conditions even at higher voltages. |
| Databáze: | OpenAIRE |
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