More than protection : The function of TiO2interlayers in hematite functionalized Si photoanodes
(2020) In Physical Chemistry Chemical Physics 22(48). p.28459-28467- Abstract
Worldwide significant efforts are ongoing to develop devices that store solar energy as fuels. In one such approach, solar energy is absorbed by semiconductors and utilized directly by catalysts at their surfaces to split water into H2 and O2. To protect the semiconductors in these photo-electrochemical cells (PEC) from corrosion, frequently thin TiO2 interlayers are applied. Employing a well-performing photoanode comprised of 1-D n-Si microwires (MWs) covered with a mesoporous (mp) TiO2 interlayer fabricated by solution processing and functionalized with α-Fe2O3 nanorods, we studied here the function of this TiO2 interlayer by high-energy resolution fluorescence detected X-ray absorption near edge structure (HERFD-XANES) spectroscopy,... (More)
Worldwide significant efforts are ongoing to develop devices that store solar energy as fuels. In one such approach, solar energy is absorbed by semiconductors and utilized directly by catalysts at their surfaces to split water into H2 and O2. To protect the semiconductors in these photo-electrochemical cells (PEC) from corrosion, frequently thin TiO2 interlayers are applied. Employing a well-performing photoanode comprised of 1-D n-Si microwires (MWs) covered with a mesoporous (mp) TiO2 interlayer fabricated by solution processing and functionalized with α-Fe2O3 nanorods, we studied here the function of this TiO2 interlayer by high-energy resolution fluorescence detected X-ray absorption near edge structure (HERFD-XANES) spectroscopy, along with X-ray emission spectroscopy (XES) and standard characterization techniques. Our data reveal that the TiO2 interlayer not only protects the n-Si MW surface from corrosion, but that it also acts as a template for the hydrothermal growth of α-Fe2O3 nanorods and improves the photocatalytic efficiency. We show that the latter effect correlates with the presence of stable oxygen vacancies at the interface between mp-TiO2 and α-Fe2O3, which act as electron traps and thereby substantially reduce the charge recombination rate at the hematite surface.
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- author
- Kawde, Anurag LU ; Annamalai, Alagappan ; Sellstedt, Anita ; Uhlig, Jens LU ; Wågberg, Thomas ; Glatzel, Pieter and Messinger, Johannes
- organization
- publishing date
- 2020
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Physical Chemistry Chemical Physics
- volume
- 22
- issue
- 48
- pages
- 9 pages
- publisher
- Royal Society of Chemistry
- external identifiers
-
- scopus:85099001289
- pmid:33295360
- ISSN
- 1463-9076
- DOI
- 10.1039/d0cp04280c
- language
- English
- LU publication?
- yes
- id
- f274ac58-1d55-4066-9896-2b2fb14a24ae
- date added to LUP
- 2021-01-21 12:56:26
- date last changed
- 2024-05-17 03:34:27
@article{f274ac58-1d55-4066-9896-2b2fb14a24ae, abstract = {{<p>Worldwide significant efforts are ongoing to develop devices that store solar energy as fuels. In one such approach, solar energy is absorbed by semiconductors and utilized directly by catalysts at their surfaces to split water into H2 and O2. To protect the semiconductors in these photo-electrochemical cells (PEC) from corrosion, frequently thin TiO2 interlayers are applied. Employing a well-performing photoanode comprised of 1-D n-Si microwires (MWs) covered with a mesoporous (mp) TiO2 interlayer fabricated by solution processing and functionalized with α-Fe2O3 nanorods, we studied here the function of this TiO2 interlayer by high-energy resolution fluorescence detected X-ray absorption near edge structure (HERFD-XANES) spectroscopy, along with X-ray emission spectroscopy (XES) and standard characterization techniques. Our data reveal that the TiO2 interlayer not only protects the n-Si MW surface from corrosion, but that it also acts as a template for the hydrothermal growth of α-Fe2O3 nanorods and improves the photocatalytic efficiency. We show that the latter effect correlates with the presence of stable oxygen vacancies at the interface between mp-TiO2 and α-Fe2O3, which act as electron traps and thereby substantially reduce the charge recombination rate at the hematite surface.</p>}}, author = {{Kawde, Anurag and Annamalai, Alagappan and Sellstedt, Anita and Uhlig, Jens and Wågberg, Thomas and Glatzel, Pieter and Messinger, Johannes}}, issn = {{1463-9076}}, language = {{eng}}, number = {{48}}, pages = {{28459--28467}}, publisher = {{Royal Society of Chemistry}}, series = {{Physical Chemistry Chemical Physics}}, title = {{More than protection : The function of TiO<sub>2</sub>interlayers in hematite functionalized Si photoanodes}}, url = {{http://dx.doi.org/10.1039/d0cp04280c}}, doi = {{10.1039/d0cp04280c}}, volume = {{22}}, year = {{2020}}, }