Reversible Redox Probes to Determine Band‐Edge Locations and Dopant Concentrations of Nano‐TiO <sub>2</sub> Thin‐Films: Settling the Mott‐Schottky Conundrum
Knowing the exact location of the semiconductor band-edges is key for mechanistic insights into their use for water and CO<sub>2</sub> photo/electrocatalysis. In this regard, a reliable strategy for nano-semiconductors did not exist yet. We demonstrate the use of reversible redox probes on nano-semiconductor electrodes to determine their band-edge locations in aqueous solutions. Rectifying current-potential (i-U) characteristics with the high work function (i.e. more positive formal potential) Fe(CN)<sub>6</sub> <sup>3-</sup>/Fe(CN)<sub>6</sub> <sup>4-</sup> redox couple yielded the exact flatband potential at various pH whereas the reversible i-U characteristics with the low work function (i.e. more negative formal potential) Ru(NH<sub>3</sub>)<sub>6</sub> <sup>3+</sup>/Ru(NH<sub>3</sub>)<sub>6</sub> <sup>2+</sup> redox couple provided the conduction band-edge location and dopant concentration for a 30 nm thin-film n-TiO<sub>2</sub>. The methodology can be extended to other nano-semiconductors and serves as an alternative to and goes beyond the capabilities of the Mott-Schottky procedure for bulk semiconductor electrodes.
Authors
- Divyansh Anil Khurana (ORCID: https://orcid.org/0000-0003-0099-2313)
- Nina Plankensteiner (ORCID: https://orcid.org/0000-0003-1375-0479)
- Philippe M. Vereecken (ORCID: https://orcid.org/0000-0003-4115-0075)
- Bart Vermang (ORCID: https://orcid.org/0000-0003-2669-2087)
Institutions
- Imec the Netherlands (NL)
- IMEC (BE)
- Hasselt University (BE)
- KU Leuven (BE)
Publication Details
- Journal
- Angewandte Chemie International Edition
- Published
- 2024-11-06
- DOI
- https://doi.org/10.1002/anie.202415857
- Citations
- 4
- Primary Topic
- Electrocatalysts for Energy Conversion
- Type
- article
- Field-Weighted Citation Impact
- 0.41
Funders
- Agentschap Innoveren en Ondernemen