Characterization of the surface redox process of caffeic acid adsorbed at glassy carbon electrodes modified with partially reduced graphene oxide
| Autor: | Sebastián Noel Robledo, Jimena Claudia Lopez, Maximiliano Andres Zensich, Gustavo M. Morales, María Alicia Zon, Héctor Fernández, Adrian Marcelo Granero |
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| Rok vydání: | 2016 |
| Předmět: |
General Chemical Engineering
PARTIALLY REDUCED GRAPHENE OXIDE Inorganic chemistry Oxide 02 engineering and technology Glassy carbon SQUARE WAVE VOLTAMMETRY Electrochemistry 01 natural sciences Redox Analytical Chemistry law.invention chemistry.chemical_compound Adsorption law Graphene Otras Ciencias Químicas 010401 analytical chemistry Ciencias Químicas 021001 nanoscience & nanotechnology 0104 chemical sciences Dielectric spectroscopy chemistry THERMODYNAMIC AND KINETICS PARAMETERS CYCLIC VOLTAMMETRY Cyclic voltammetry 0210 nano-technology CAFFEIC ACID CIENCIAS NATURALES Y EXACTAS |
| Zdroj: | Journal of Electroanalytical Chemistry. 783:258-267 |
| ISSN: | 1572-6657 |
| DOI: | 10.1016/j.jelechem.2016.11.012 |
| Popis: | This paper describes for the first time the caffeic acid (CA) electrochemical oxidation in 1.0 M HClO4 and phosphate buffer solutions (PBS) of different pH at glassy carbon electrodes (GCE) modified with electrochemically partially reduced graphene oxide (GCE/ePRGO) using cyclic and square wave voltammetries. A quasi-reversible surface redox couple was found in all reaction media at this modified electrode. The Box-Behnken design (BBD) statistical experiments and the surface methodology (RSM) were used to optimize experimental variables to generate the GCE/ePRGO. Atomic force microscopy (AFM) and electrochemical impedance spectroscopy (EIS) were used as the techniques to characterize the surface of modified electrodes. EIS was also used to determine a tentative electrochemical area for the GCE/ePRGO. The Frumkin adsorption isotherm was the best which describes the specific interaction of CA with CGE/ePRGO. The thermodynamic and kinetics of the surface redox couple were studied in 1.0 M HClO4. Therefore, we used the methods of the “quasi-reversible maximum” and the “splitting of the net SW voltammetric peak” to obtain information about the thermodynamic and kinetics of this surface redox couple. Averages values obtained for the formal potential and the anodic transfer coefficient were (0.638 ± 0.005) V and (0.58 ± 0.06), respectively. A value of 40 s− 1 was obtained for the overall formal rate constant. For comparison, CA electrochemical responses were also studied at bare GCE, and GCE modified with a dispersion of graphene oxide (GCE/GO). Fil: Robledo, Sebastian Noel. Universidad Nacional de Rio Cuarto. Facultad de Ingeniería. Departamento de Tecnología Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: López, Jimena Claudia. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Granero, Adrian Marcelo. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Zensich, Maximiliano Andres. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Morales, Gustavo Marcelo. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Fernandez, Hector. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Zon, María Alicia. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina |
| Databáze: | OpenAIRE |
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