Photoelectrochemical reduction rate of ferricyanide at different TiO2 forms: comparison of SECM and cyclic voltammetric results
| Autor: | Surawut Chuangchote, Mithran Somasundrum, Benchaporn Lertanantawong, Werasak Surareungchai, Panjaphong Lertsathitphong, Manoj Devkota, Chan La-o-vorakiat |
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| Rok vydání: | 2021 |
| Předmět: |
Anatase
Working electrode Materials science Analytical chemistry 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics Rate-determining step 01 natural sciences 0104 chemical sciences Amorphous solid chemistry.chemical_compound Reaction rate constant chemistry Electrode Electrochemistry General Materials Science Ferricyanide Electrical and Electronic Engineering Cyclic voltammetry 0210 nano-technology |
| Zdroj: | Journal of Solid State Electrochemistry. 25:1691-1698 |
| ISSN: | 1433-0768 1432-8488 |
| DOI: | 10.1007/s10008-021-04928-8 |
| Popis: | The heterogeneous rate constant (k) for the reduction of Fe(CN)63- at different UV-illuminated TiO2 polymorphs was determined by (1) cyclic voltammetry (CV) where a TiO2-modified fluorine-doped tin oxide (FTO)-coated glass was the working electrode, and (2) SECM approach curves at the same electrodes at open circuit. The combination of Fe(CN)63- with photogenerated electrons was found to be the rate determining step. The magnitude of the SECM values of k were in the order: anatase-rutile > anatase > rutile > amorphous, which agrees with the generally accepted photocatalytic efficiencies of the TiO2 polymorphs. In contrast, the CV-determined values of k followed the sequence: amorphous > rutile > anatase-rutile > anatase and were approximately one order of magnitude lower than the SECM-determined values. We suggest this indicates the CV determination of rate constants at photoactive films is problematic, due to factors such as reaction at the underlying electrode and the uncompensated resistance of the film. |
| Databáze: | OpenAIRE |
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