CoP as an Acid-Stable Active Electrocatalyst for the Hydrogen-Evolution Reaction: Electrochemical Synthesis, Interfacial Characterization and Performance Evaluation
| العنوان: | CoP as an Acid-Stable Active Electrocatalyst for the Hydrogen-Evolution Reaction: Electrochemical Synthesis, Interfacial Characterization and Performance Evaluation |
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| المؤلفون: | John C. Hemminger, Nathan S. Lewis, Erik Verlage, Fadl H. Saadi, Manuel P. Soriaga, Azhar I. Carim |
| المصدر: | The Journal of Physical Chemistry C. 118:29294-29300 |
| بيانات النشر: | American Chemical Society (ACS), 2014. |
| سنة النشر: | 2014 |
| مصطلحات موضوعية: | Materials science, Phosphide, Inorganic chemistry, chemistry.chemical_element, Electrochemistry, Electrocatalyst, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Catalysis, symbols.namesake, chemistry.chemical_compound, General Energy, chemistry, X-ray photoelectron spectroscopy, symbols, Physical and Theoretical Chemistry, Cyclic voltammetry, Raman spectroscopy, Cobalt |
| الوصف: | Films of CoP have been electrochemically synthesized, characterized, and evaluated for performance as a catalyst for the hydrogen-evolution reaction (HER). The film was synthesized by cathodic deposition from a boric acid solution of Co^(2+) and H_2PO_2^– on copper substrates followed by operando remediation of exogenous contaminants. The films were characterized structurally and compositionally by scanning-electron microscopy, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and Raman spectrophotometry. The catalytic activity was evaluated by cyclic voltammetry and chronopotentiometry. Surface characterization prior to electrocatalysis indicated that the film consisted of micrometer-sized spherical clusters located randomly and loosely on a slightly roughened surface. The composition of both the clusters and surface consisted of cobalt in the metallic, phosphide, and amorphous-oxide forms (CoO·Co_2O_3) and of phosphorus as phosphide and orthophosphate. The orthophosphate species, produced by air-oxidation, were eliminated upon HER electrocatalysis in sulfuric acid. The operando film purification yielded a functional electrocatalyst with a Co:P stoichiometric ratio of 1:1. After the HER, the surface was densely packed with micrometer-sized, mesa-like particles whose tops were flat and smooth. The CoP eletrodeposit exhibited an 85 mV overvoltage (η) for the HER at a current density of 10 mA cm^(–2) and was stable under operation in highly acidic solution, with an increase in η of 18 mV after 24 h of continuous operation. The comparative HER catalytic performance of CoP, film or nanoparticles, is as follows: η_(Pt) < η_(CoP film) = η_(CoP NP), η_(Ni_2P) < η_(CoSe)_2 < η_(MoS)_2 < η_(MoSe)_2. |
| وصف الملف: | application/pdf |
| تدمد: | 1932-7455 1932-7447 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::5f72f96096187dc18b7d6f8be621c2cf https://doi.org/10.1021/jp5054452 |
| حقوق: | OPEN |
| رقم الأكسشن: | edsair.doi.dedup.....5f72f96096187dc18b7d6f8be621c2cf |
| قاعدة البيانات: | OpenAIRE |
Find this issue from the American Chemical Society | تدمد: | 19327455 19327447 |
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