Abstract
Photoelectrochemical processes are investigated for chromoionophoreI (ETH 5294) dissolved in 4-(3-phenylpropyl)pyridine (PPP) and deposited in the form of a microdroplet array (through evaporation deposition from a solution in acetonitrile) onto a 5mm diameter basal plane pyrolytic graphite (BPPG) electrode. Stable biphasic dark voltammetric responses (two electron/two proton) are observed in phosphate buffer solution (from pH2 to 12) with a switch in reactivity at pH5 due to a biphasic protonation step. The photoelectrochemical activity at pH2 is investigated further by phototransient amperometry. The protonated chromoionophoreI is shown to be the photoactive component (supported by EPR data) and "hole transfer" at the liquid|liquid interface to aqueous oxalate is demonstrated. This interfacial hole-transfer process can be "switched off" by hydrophobic anions (PF6-), which compete for cationic liquid|liquid PPP surface binding sites. Implications for light harvesting and liquid semiconductor properties are discussed.
Original language | English |
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Pages (from-to) | 400-406 |
Number of pages | 7 |
Journal | ChemElectroChem |
Volume | 1 |
Issue number | 2 |
DOIs | |
Publication status | Published - 1 Feb 2014 |
Keywords
- Chromoionophores
- Electrochemistry
- Interfaces
- Photochemistry
- Semiconductors