Trivalent iron rich CoFe layered oxyhydroxides for electrochemical water oxidation
| Autor: | Wolfgang Schuhmann, Swapnil Varhade, A. V. Radha, Michael Ertl, Sebastian Weiß, Corina Andronescu, Josef Breu |
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| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Chemistry
General Chemical Engineering Inorganic chemistry Oxygen evolution Layered double hydroxides Chemie 02 engineering and technology engineering.material 010402 general chemistry 021001 nanoscience & nanotechnology Electrochemistry 01 natural sciences 0104 chemical sciences chemistry.chemical_compound Electron transfer Octahedron Transition metal engineering High activity Carbonate 0210 nano-technology |
| Popis: | Layered double hydroxides (LDHs) are presently among the best-performing oxygen evolution reaction (OER) electrocatalysts in alkaline media. The high activity of LDHs is due to synergistic effects between two transition metals as well as the layered structure which facilitates electron transfer. Because of a perfect match with the size of interlayer carbonate a ratio of 2:1 for the di- and tri-valent octahedral cations is energetically preferred. Here we present a strategy, where first mixed valent (Co2+1-zFe2+z)4 Fe3+2 - LDHs, with z values between 0 and 0.75 are synthesized, which are subsequently oxidized to Co2+Fe3+ LDH-type layered (oxy)hydroxides with an unusual high trivalent Fe content. Characterization of the chemically oxidized materials using bulk and surface techniques demonstrated the successful synthesis of LDH-like trivalent iron rich (Co2+)4-4z (Fe3+)2+4z (oxy)hydroxides with a final Fe content ranging from 33.3 to 83.3%. Current densities of up to 200 mA cm−2 were obtained at potentials lower than 1.7 V vs. RHE for (Co2+)4-4z (Fe3+)2+4z (oxy)hydroxides containing a maximum of 80% Fe. |
| Databáze: | OpenAIRE |
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