Interplay Between Charge Accumulation and Oxygen Reduction Catalysis in Nanostructured TiO<sub>2</sub> Electrodes Functionalized with a Molecular Catalyst
Bibliographic record
Abstract
Abstract The catalytic reduction of O 2 by a manganese(III) porphyrin immobilized in a nanostructured semiconductive transparent TiO 2 electrode is here investigated by UV‐Vis spectroelectrochemistry in an aqueous buffered medium. Analysis of the operando spectroelectrochemical data, collected for both the immobilized catalyst and the TiO 2 matrix, demonstrates the coexistence of two faradaic electrochemical processes, namely ( i ) irreversible interfacial electron transfer from TiO 2 to the immobilized porphyrin triggering the catalytic reduction of O 2 , and ( ii ) reversible proton‐coupled electrochemical reduction of TiO 2 leading to the accumulation of electrons in the TiO 2 bulk. The competition between these two processes is modulated by the local concentration of O 2 , which itself varies with the rate of the catalysis. Indeed, when O 2 is locally strongly depleted by catalysis, the process switches from catalysis to charge storage, like a battery. As a result, the electrons stored in TiO 2 were observed to pursue the catalysis even after the electrode polarization was switched‐off ( i. e ., under open circuit). This is an overlooked phenomenon that we believe is important to consider in applications relying on metal oxide‐based photoelectrodes operating in aqueous media.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".