Spectroelectrochemical Detection of Water Dissociation in Bipolar Membranes
| Autor: | Apurva Shantilal Gangrade, Amelia Hohenadel, Steven Holdcroft |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Materials science
Ion exchange Limiting current Analytical chemistry 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology Electrochemistry 01 natural sciences 6. Clean water Dissociation (chemistry) 0104 chemical sciences Dielectric spectroscopy Ion chemistry.chemical_compound Membrane chemistry pH indicator General Materials Science 0210 nano-technology |
| Zdroj: | ACS applied materialsinterfaces. 13(38) |
| ISSN: | 1944-8252 |
| Popis: | The potentials at which water dissociation occurs in bipolar membranes (BPM) and the relationship between water dissociation and current-voltage curve characteristics are explored using a novel spectroelectrochemical approach in which an anion exchange membrane is doped with a pH indicator. Using this method, we visually detect a pH change in the BPM resulting from OH- formed during the water dissociation reaction. The color change is measured with a UV/vis spectrometer, while electrochemical characterization of the BPM is performed simultaneously. Additional measurements were performed on BPMs with varying anion and cation exchange membrane layer thickness. Our measurements provide direct evidence of water dissociation occurring within a BPM at cross-membrane potentials below 0.5 V, within the first limiting current density region. We also show that the effects of changing bulk anion and cation exchange layer thickness is highly dependent on the permselectivity of these layers. |
| Databáze: | OpenAIRE |
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