Formation, characterization and electrocatalytic activity of layer-by-layer self-assembled films containing polyoxomolybdate over Au surfaces
We describe a novel strategy for the controlled fabrication of well-defined multilayer films incorporating a polyoxomolybdate anion (PMo12O403-, POM) via ion exchange on Au electrodes. Composite films were thoroughly characterized by ellipsometry, X-ray photoelectron spectroscopy (XPS), FTIR-ATR, qu...
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2012
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_15726657_v673_n_p1_Volker http://hdl.handle.net/20.500.12110/paper_15726657_v673_n_p1_Volker |
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paper:paper_15726657_v673_n_p1_Volker2023-06-08T16:24:48Z Formation, characterization and electrocatalytic activity of layer-by-layer self-assembled films containing polyoxomolybdate over Au surfaces Electrocatalysis Ion exchange Layer-by-layer Polyoxomolybdate Self assembly Composite films Cyclic voltammetry Electrocatalysis Electrocatalysts Gold Ion exchange Molecules Multilayer films Photoelectrons Self assembly X ray photoelectron spectroscopy Au electrodes Au surfaces Basic solutions Electrocatalytic activity Electrochemical behaviors Film electrodes FT-IR-ATR Initial loss Keggin structure Layer-by-layers Modified electrodes Novel strategies Peak potentials Peroxodisulfate pH value PH-dependent PMo12O403 Polyoxomolybdates Redox process Room temperature Self assembled films XPS measurements Electrochemical electrodes We describe a novel strategy for the controlled fabrication of well-defined multilayer films incorporating a polyoxomolybdate anion (PMo12O403-, POM) via ion exchange on Au electrodes. Composite films were thoroughly characterized by ellipsometry, X-ray photoelectron spectroscopy (XPS), FTIR-ATR, quartz crystal microbalance (QCM) and cyclic voltammetry (CV). XPS and FTIR-ATR measurements showed that the Keggin structure of polyoxomolybdates is maintained as they are incorporated into the film. QCM experiments demonstrated that larger amounts of POM are incorporated into thicker film electrodes. EQCM and XPS measurements further showed that part of the film is delaminated when the modified electrodes were submerged in acid or basic solutions, but after this initial loss of mass the electrodes remain stable in time and with electrochemical use. POM-modified electrodes showed a pH-dependent electrochemical behavior, with peak potentials shifting by -60 mV pH-1, characteristic of a 2e/2H+ redox process at room temperature. Furthermore, our results suggest that POM molecules in the film are not decomposed when the electrodes are immersed in solutions with pH = 4.8 a key finding as POM molecules in solution suffer from complete hydrolysis at this pH value. Finally, the performance of these POM-modified electrodes as electrocatalysts was assessed via the reduction of nitrite, chlorate and peroxodisulfate. © 2012 Elsevier B.V. All rights reserved. 2012 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_15726657_v673_n_p1_Volker http://hdl.handle.net/20.500.12110/paper_15726657_v673_n_p1_Volker |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
Electrocatalysis Ion exchange Layer-by-layer Polyoxomolybdate Self assembly Composite films Cyclic voltammetry Electrocatalysis Electrocatalysts Gold Ion exchange Molecules Multilayer films Photoelectrons Self assembly X ray photoelectron spectroscopy Au electrodes Au surfaces Basic solutions Electrocatalytic activity Electrochemical behaviors Film electrodes FT-IR-ATR Initial loss Keggin structure Layer-by-layers Modified electrodes Novel strategies Peak potentials Peroxodisulfate pH value PH-dependent PMo12O403 Polyoxomolybdates Redox process Room temperature Self assembled films XPS measurements Electrochemical electrodes |
| spellingShingle |
Electrocatalysis Ion exchange Layer-by-layer Polyoxomolybdate Self assembly Composite films Cyclic voltammetry Electrocatalysis Electrocatalysts Gold Ion exchange Molecules Multilayer films Photoelectrons Self assembly X ray photoelectron spectroscopy Au electrodes Au surfaces Basic solutions Electrocatalytic activity Electrochemical behaviors Film electrodes FT-IR-ATR Initial loss Keggin structure Layer-by-layers Modified electrodes Novel strategies Peak potentials Peroxodisulfate pH value PH-dependent PMo12O403 Polyoxomolybdates Redox process Room temperature Self assembled films XPS measurements Electrochemical electrodes Formation, characterization and electrocatalytic activity of layer-by-layer self-assembled films containing polyoxomolybdate over Au surfaces |
| topic_facet |
Electrocatalysis Ion exchange Layer-by-layer Polyoxomolybdate Self assembly Composite films Cyclic voltammetry Electrocatalysis Electrocatalysts Gold Ion exchange Molecules Multilayer films Photoelectrons Self assembly X ray photoelectron spectroscopy Au electrodes Au surfaces Basic solutions Electrocatalytic activity Electrochemical behaviors Film electrodes FT-IR-ATR Initial loss Keggin structure Layer-by-layers Modified electrodes Novel strategies Peak potentials Peroxodisulfate pH value PH-dependent PMo12O403 Polyoxomolybdates Redox process Room temperature Self assembled films XPS measurements Electrochemical electrodes |
| description |
We describe a novel strategy for the controlled fabrication of well-defined multilayer films incorporating a polyoxomolybdate anion (PMo12O403-, POM) via ion exchange on Au electrodes. Composite films were thoroughly characterized by ellipsometry, X-ray photoelectron spectroscopy (XPS), FTIR-ATR, quartz crystal microbalance (QCM) and cyclic voltammetry (CV). XPS and FTIR-ATR measurements showed that the Keggin structure of polyoxomolybdates is maintained as they are incorporated into the film. QCM experiments demonstrated that larger amounts of POM are incorporated into thicker film electrodes. EQCM and XPS measurements further showed that part of the film is delaminated when the modified electrodes were submerged in acid or basic solutions, but after this initial loss of mass the electrodes remain stable in time and with electrochemical use. POM-modified electrodes showed a pH-dependent electrochemical behavior, with peak potentials shifting by -60 mV pH-1, characteristic of a 2e/2H+ redox process at room temperature. Furthermore, our results suggest that POM molecules in the film are not decomposed when the electrodes are immersed in solutions with pH = 4.8 a key finding as POM molecules in solution suffer from complete hydrolysis at this pH value. Finally, the performance of these POM-modified electrodes as electrocatalysts was assessed via the reduction of nitrite, chlorate and peroxodisulfate. © 2012 Elsevier B.V. All rights reserved. |
| title |
Formation, characterization and electrocatalytic activity of layer-by-layer self-assembled films containing polyoxomolybdate over Au surfaces |
| title_short |
Formation, characterization and electrocatalytic activity of layer-by-layer self-assembled films containing polyoxomolybdate over Au surfaces |
| title_full |
Formation, characterization and electrocatalytic activity of layer-by-layer self-assembled films containing polyoxomolybdate over Au surfaces |
| title_fullStr |
Formation, characterization and electrocatalytic activity of layer-by-layer self-assembled films containing polyoxomolybdate over Au surfaces |
| title_full_unstemmed |
Formation, characterization and electrocatalytic activity of layer-by-layer self-assembled films containing polyoxomolybdate over Au surfaces |
| title_sort |
formation, characterization and electrocatalytic activity of layer-by-layer self-assembled films containing polyoxomolybdate over au surfaces |
| publishDate |
2012 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_15726657_v673_n_p1_Volker http://hdl.handle.net/20.500.12110/paper_15726657_v673_n_p1_Volker |
| _version_ |
1768541957236195328 |