Operando DRIFTS Proof of Visible-Light-Activated Surface Reduction of WO<sub>3</sub>: Implication for Gas Sensing
The interaction of oxygen and water vapor with the surface of WO3 gas sensors at elevated temperature is well understood. Alternative to heat, illumination with light of different wavelengths at low temperature provides the necessary activation energy for surface reactions. In this study, operando diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) was employed to investigate and compare the effects of illumination and thermal activation at the molecular level. Photodesorption of oxygen, even by photons with energies below the bandgap, was identified as the key process in light-activated gas sensing with WO3. Furthermore, oxygen and water vapor were found to act as competitive analytes under illumination, highlighting the complex interplay of surface adsorption and desorption processes in light-activated sensing. The contrasts observed between light and heat activation are the probable reason for different selectivities.
Authors
- Benjamin Junker (ORCID: https://orcid.org/0000-0002-2229-0534)
- Udo Weimar (ORCID: https://orcid.org/0000-0003-2354-0432)
- Nicolae Bârsan (ORCID: https://orcid.org/0000-0001-6718-9889)
- Xiaoxue Wang (ORCID: https://orcid.org/0000-0003-4581-537X)
Institutions
- University of Bremen (DE)
- Sensors (United States) (US)
- Division of Materials Science and Engineering (AU)
- Materials Processing (United States) (US)
- State Key Laboratory of Materials Processing and Die & Mould Technology (CN)
- Huazhong University of Science and Technology (CN)
- University of Tübingen (DE)
- Kumamoto University (JP)
Publication Details
- Journal
- The Journal of Physical Chemistry C
- Published
- 2025-05-14
- DOI
- https://doi.org/10.1021/acs.jpcc.5c01808
- Citations
- 2
- Primary Topic
- Gas Sensing Nanomaterials and Sensors
- Type
- article
- Field-Weighted Citation Impact
- 1.46
Funders
- National Natural Science Foundation of China