Controlling the mixed potential of polyelectrolyte-coated platinum electrodes for the potentiometric detection of hydrogen peroxide
| Autor: | Sylviane Chahrati, Rocío Cánovas, Jhonattan F. Baez, Francisco J. Andrade, Pascal Blondeau, Matthew Compton |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Chemistry
010401 analytical chemistry Potentiometric titration chemistry.chemical_element 02 engineering and technology engineering.material 021001 nanoscience & nanotechnology 01 natural sciences Biochemistry Polyelectrolyte 0104 chemical sciences Analytical Chemistry chemistry.chemical_compound Coating Chemical engineering Nafion Electrode engineering Environmental Chemistry 0210 nano-technology Hydrogen peroxide Platinum Biosensor Spectroscopy |
| Zdroj: | Analytica Chimica Acta. 1097:204-213 |
| ISSN: | 0003-2670 |
| DOI: | 10.1016/j.aca.2019.11.018 |
| Popis: | The use of a Pt electrode coated with a layer of Nafion has been described in previous works as an attractive way to perform the potentiometric detection of hydrogen peroxide. Despite of the attractive features of this approach, the nature of the non-Nernstian response of this system was not properly addressed. In this work, using a mixed potential model, the open circuit potential of the Pt electrode is shown to be under kinetic control of the oxygen reduction reaction (ORR). It is proposed that hydrogen peroxide acts as an oxygenated species that blocks free sites on the Pt surface, interfering with the ORR. Therefore, the effect of the polyelectrolyte coating can be understood in terms of the modulation of the factors that affects the kinetics of the ORR, such as an increase of the H+ concentration, minimization of the effect of the spectator species, etc. Because of the complexity and the lack of models that accurately describe systems with practical applications, this work is not intended to provide a mechanistic but rather a phenomenological view on problem. A general framework to understand the factors that affect the potentiometric response is provided. Experimental evidence showing that the use of polyelectrolyte coatings are a powerful way to control the mixed potential open new ways for the development of robust and simple potentiometric sensors. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect