Abstract
Protonation of the molecularly rigid polymer of intrinsic microporosity PIM-EA-TB can be coupled to immobilisation of Fe(CN) 6 3−/4− (as well as immobilisation of Prussian blue) into 1–2 nm diameter channels. The resulting films provide redox-active coatings on glassy carbon electrodes. Uptake, transport, and retention of Fe(CN) 6 3−/4− in the microporous polymer are strongly pH dependent requiring protonation of the PIM-EA-TB (pK A ≈ 4). Both Fe(CN) 6 4− and Fe(CN) 6 3− can be immobilised, but Fe(CN) 6 4− appears to bind tighter to the polymer backbone presumably via bridging protons. Loss of Fe(CN) 6 3−/4− by leaching into the aqueous solution phase becomes significant only at pH > 9 and is likely to be associated with hydroxide anions directly entering the microporous structure to combine with protons. This and the interaction of Fe(CN) 6 3−/4− and protons within the molecularly rigid PIM-EA-TB host are suggested to be responsible for retention and relatively slow leaching processes. Electrocatalysis with immobilised Fe(CN) 6 3−/4− is demonstrated for the oxidation of ascorbic acid. [Figure not available: see fulltext.].
Original language | English |
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Pages (from-to) | 2797-28067 |
Journal | Journal of Solid State Electrochemistry |
Volume | 24 |
Early online date | 26 Apr 2020 |
DOIs | |
Publication status | Published - 30 Nov 2020 |
Keywords
- Coordination polymer
- Electrocatalysis
- Membrane
- Porosity
- Sensor
- Voltammetry
ASJC Scopus subject areas
- General Materials Science
- Condensed Matter Physics
- Electrochemistry
- Electrical and Electronic Engineering