Electrocatalytic Performance and Stability of Nanostructured Fe–Ni Pyrite-Type Diphosphide Catalyst Supported on Carbon Paper
| Autor: | M. Fátima Cerqueira, Kirill Kovnir, Enrique Carbó-Argibay, Carlos Rodríguez-Abreu, José Luis Lado, Juan Gallo, Elvira Paz, Yury V. Kolen'ko, J. D. Costa |
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| Přispěvatelé: | Universidade do Minho |
| Rok vydání: | 2016 |
| Předmět: |
Working electrode
Materials science Inorganic chemistry 02 engineering and technology Electrolyte Engenharia Química [Engenharia e Tecnologia] 010402 general chemistry Electrocatalyst Electrochemistry Electrocatalytic 01 natural sciences 7. Clean energy Physical and Theoretical Chemistry Tafel equation Science & Technology Oxygen evolution 021001 nanoscience & nanotechnology Nanostructures 0104 chemical sciences Surfaces Coatings and Films Electronic Optical and Magnetic Materials Anode General Energy Water splitting 0210 nano-technology Engenharia e Tecnologia::Engenharia Química Fe–Ni Pyrite Carbon Paper |
| Zdroj: | The Journal of Physical Chemistry C Repositório Científico de Acesso Aberto de Portugal Repositório Científico de Acesso Aberto de Portugal (RCAAP) instacron:RCAAP |
| ISSN: | 1932-7447 |
| DOI: | 10.1021/acs.jpcc.6b05783 |
| Popis: | A simple and effective method to prepare an active and stable nanostructured working electrode for electrochemical water splitting is described. Specifically, mixed Fe–Ni diphosphide was prepared by sputtering a 200-nm-thick layer of Permalloy onto carbon paper gas diffusion layer followed by gas transport phosphorization reaction. The mass density of the resultant diphosphide phase was established to be 1.1 mg/cm2. Energy-dispersive X-ray microanalysis shows that the actual elemental composition of the resultant ternary electrocatalyst is approximately Fe0.2Ni0.8P2, while the powder X-ray diffraction analysis confirms that the electrocatalyst crystallizes in NiP2 cubic pyrite-like structure. As a cathode for hydrogen evolution reaction (HER) in acidic and alkaline electrolytes, this earth-abundant electrode has exchange current densities of 6.84103 and 3.16103 mA/cm2 and Tafel slopes of 55.3 and 72.2 mV/dec, respectively. As an anode for oxygen evolution reaction (OER) in alkaline electrolyte, the electrode shows an exchange current density of 2.88104 mA/cm2 and Tafel slope of 49.3 mV/dec. The observed high activity of the electrode correlates well with its electronic structure, which was assessed by density functional theory (DFT) calculations. The stability of Fe0.2Ni0.8P2 electrocatalyst in HER and OER was evaluated by means of accelerated degradation test and chronopotentiometry. The results of these experiments elucidate partial dissolution and entire chemical transformation of Fe0.2Ni0.8P2 as the main mechanisms of the electrode degradation during HER and OER, respectively. Overall, our findings could facilitate the composition-based design of active, stable, and durable phosphide electrodes for electrochemical water splitting. We thank all members of the Nanomaterials Synthesis Unit at the INL for their fruitful scientific and technical input, as well as Dr. X. Wang for his help with the electrocatalytic data analysis. This investigation has benefited from the financial support provided by the European Union Horizon 2020 NMP programme through the CritCat project under grant agreement no. 686053, as well as ERDF funds through the Portuguese Operational Programme for Competitiveness and Internationalization (COMPETE 2020), and National Funds through the Portuguese Foundation for Science and Technology (FCT), under the PrintPV project PTDC/CTM-ENE/5387/2014 (grant agreement no. 016663). J.D.C. thanks the FCT PhD grant SFRH/BD/79393/2011, while J.L.L. thanks Marie-Curie-ITN607904-SPINOGRAPH project for the PhD grant. |
| Databáze: | OpenAIRE |
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