Abstract
We report a method to study electro-active defects in passivated electrodes. This method couples fluorescence microscopy and electrochemistry to localize and size electro-active defects. The method was validated by comparison with a scanning probe technique, scanning electrochemical microscopy. We used our method for studying electro-active defects in thin TiO2 layers electrodeposited on 25 μm diameter Pt ultramicroelectrodes (UMEs). The permeability of the TiO2 layer was estimated by measuring the oxidation of ferrocenemethanol at the UME. Blocking of current ranging from 91.4 to 99.8% was achieved. Electro-active defects with an average radius ranging between 9 and 90 nm were observed in these TiO2 blocking layers. The distribution of electro-active defects over the TiO2 layer is highly inhomogeneous and the number of electro-active defect increases for lower degree of current blocking. The interest of the proposed technique is the possibility to quickly (less than 15 min) image samples as large as several hundreds of μm2 while being able to detect electro-active defects of only a few tens of nm in radius.
| Original language | English |
|---|---|
| Pages (from-to) | 5730-5737 |
| Number of pages | 8 |
| Journal | Analytical Chemistry |
| Volume | 87 |
| Issue number | 11 |
| DOIs | |
| Publication status | Published - 2015 Jun 2 |
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All Science Journal Classification (ASJC) codes
- Analytical Chemistry
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Observation of nanometer-sized electro-active defects in insulating layers by fluorescence microscopy and electrochemistry. / Renault, Christophe; Marchuk, Kyle; Ahn, Hyun S.; Titus, Eric J.; Kim, Jiyeon; Willets, Katherine A.; Bard, Allen J.
In: Analytical Chemistry, Vol. 87, No. 11, 02.06.2015, p. 5730-5737.Research output: Contribution to journal › Article
TY - JOUR
T1 - Observation of nanometer-sized electro-active defects in insulating layers by fluorescence microscopy and electrochemistry
AU - Renault, Christophe
AU - Marchuk, Kyle
AU - Ahn, Hyun S.
AU - Titus, Eric J.
AU - Kim, Jiyeon
AU - Willets, Katherine A.
AU - Bard, Allen J.
PY - 2015/6/2
Y1 - 2015/6/2
N2 - We report a method to study electro-active defects in passivated electrodes. This method couples fluorescence microscopy and electrochemistry to localize and size electro-active defects. The method was validated by comparison with a scanning probe technique, scanning electrochemical microscopy. We used our method for studying electro-active defects in thin TiO2 layers electrodeposited on 25 μm diameter Pt ultramicroelectrodes (UMEs). The permeability of the TiO2 layer was estimated by measuring the oxidation of ferrocenemethanol at the UME. Blocking of current ranging from 91.4 to 99.8% was achieved. Electro-active defects with an average radius ranging between 9 and 90 nm were observed in these TiO2 blocking layers. The distribution of electro-active defects over the TiO2 layer is highly inhomogeneous and the number of electro-active defect increases for lower degree of current blocking. The interest of the proposed technique is the possibility to quickly (less than 15 min) image samples as large as several hundreds of μm2 while being able to detect electro-active defects of only a few tens of nm in radius.
AB - We report a method to study electro-active defects in passivated electrodes. This method couples fluorescence microscopy and electrochemistry to localize and size electro-active defects. The method was validated by comparison with a scanning probe technique, scanning electrochemical microscopy. We used our method for studying electro-active defects in thin TiO2 layers electrodeposited on 25 μm diameter Pt ultramicroelectrodes (UMEs). The permeability of the TiO2 layer was estimated by measuring the oxidation of ferrocenemethanol at the UME. Blocking of current ranging from 91.4 to 99.8% was achieved. Electro-active defects with an average radius ranging between 9 and 90 nm were observed in these TiO2 blocking layers. The distribution of electro-active defects over the TiO2 layer is highly inhomogeneous and the number of electro-active defect increases for lower degree of current blocking. The interest of the proposed technique is the possibility to quickly (less than 15 min) image samples as large as several hundreds of μm2 while being able to detect electro-active defects of only a few tens of nm in radius.
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U2 - 10.1021/acs.analchem.5b00898
DO - 10.1021/acs.analchem.5b00898
M3 - Article
AN - SCOPUS:84930621528
VL - 87
SP - 5730
EP - 5737
JO - Analytical Chemistry
JF - Analytical Chemistry
SN - 0003-2700
IS - 11
ER -