Details
| Original language | English |
|---|---|
| Article number | 111349 |
| Journal | Solar Energy Materials and Solar Cells |
| Volume | 232 |
| Early online date | 4 Sept 2021 |
| Publication status | Published - Oct 2021 |
Abstract
Oxygen evolution is kinetically the key step in the photocatalytic water splitting, but it is negatively affected by the poor charge transport properties. However, this can be modified by the loading of cocatalysts on the surface of a semiconductor which could form heterojunctions to boost the charge separation and lower the activation potential for O 2 evolution. In this paper we demonstrate that the poor O 2 evolution activity of photocatalytic water splitting of the multiferroics BiFeO 3 can be enhanced when a proper cocatalyst like IrO 2 nanoparticles are deposited on the surface and proper electron scavenger is used. The choice of the persulfate, S 2O 8 as electron scavenger is influenced by its high redox potential and its close position to the valence band of BiFeO 3 compared to other commonly used scavengers. Another interesting information was revealed by using transient absorption spectroscopy under different environment namely, inert, oxidizing and reducing. The absorption peak of holes was identified and correlated to the strong absorption around 560 nm The hole absorption peak showed a 50% decrease in the absorption intensity after 2.5 μsec indicating that holes are captured by IrO 2 nanoparticles on the surface. O 2 evolution of multiferroics, especially BiFeO 3 has been less investigated. Therefore, the development of efficient photocatalytic materials has relied on both photocatalysts and cocatalysts. Identification of the photogenerated charge absorption peak from transient absorption spectra facilitate the evaluation of the IrO 2 loading effect on the charge separation and the overall O 2 evolution process.
Keywords
- BiFeO3, IrO2 cocatalyst, Molecular oxygen evolution, Photocatalysis, Transient absorption spectroscopy
ASJC Scopus subject areas
- Materials Science(all)
- Electronic, Optical and Magnetic Materials
- Materials Science(all)
- Surfaces, Coatings and Films
- Energy(all)
- Renewable Energy, Sustainability and the Environment
Sustainable Development Goals
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In: Solar Energy Materials and Solar Cells, Vol. 232, 111349, 10.2021.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Assessing the photocatalytic oxygen evolution reaction of BiFeO3 loaded with IrO2 nanoparticles as cocatalyst
AU - Ramadan, Wegdan
AU - Feldhoff, Armin
AU - Bahnemann, Detlef
N1 - Funding Information: One of the authors, Wegdan Ramadan, would like to express gratitude to the Alexander von Humboldt Foundation for the fellowship and the financial subsidy towards the purchase of equipment. We would like also to thank Dr. Ralf Dillert for the fruitful discussion.
PY - 2021/10
Y1 - 2021/10
N2 - Oxygen evolution is kinetically the key step in the photocatalytic water splitting, but it is negatively affected by the poor charge transport properties. However, this can be modified by the loading of cocatalysts on the surface of a semiconductor which could form heterojunctions to boost the charge separation and lower the activation potential for O 2 evolution. In this paper we demonstrate that the poor O 2 evolution activity of photocatalytic water splitting of the multiferroics BiFeO 3 can be enhanced when a proper cocatalyst like IrO 2 nanoparticles are deposited on the surface and proper electron scavenger is used. The choice of the persulfate, S 2O 8 as electron scavenger is influenced by its high redox potential and its close position to the valence band of BiFeO 3 compared to other commonly used scavengers. Another interesting information was revealed by using transient absorption spectroscopy under different environment namely, inert, oxidizing and reducing. The absorption peak of holes was identified and correlated to the strong absorption around 560 nm The hole absorption peak showed a 50% decrease in the absorption intensity after 2.5 μsec indicating that holes are captured by IrO 2 nanoparticles on the surface. O 2 evolution of multiferroics, especially BiFeO 3 has been less investigated. Therefore, the development of efficient photocatalytic materials has relied on both photocatalysts and cocatalysts. Identification of the photogenerated charge absorption peak from transient absorption spectra facilitate the evaluation of the IrO 2 loading effect on the charge separation and the overall O 2 evolution process.
AB - Oxygen evolution is kinetically the key step in the photocatalytic water splitting, but it is negatively affected by the poor charge transport properties. However, this can be modified by the loading of cocatalysts on the surface of a semiconductor which could form heterojunctions to boost the charge separation and lower the activation potential for O 2 evolution. In this paper we demonstrate that the poor O 2 evolution activity of photocatalytic water splitting of the multiferroics BiFeO 3 can be enhanced when a proper cocatalyst like IrO 2 nanoparticles are deposited on the surface and proper electron scavenger is used. The choice of the persulfate, S 2O 8 as electron scavenger is influenced by its high redox potential and its close position to the valence band of BiFeO 3 compared to other commonly used scavengers. Another interesting information was revealed by using transient absorption spectroscopy under different environment namely, inert, oxidizing and reducing. The absorption peak of holes was identified and correlated to the strong absorption around 560 nm The hole absorption peak showed a 50% decrease in the absorption intensity after 2.5 μsec indicating that holes are captured by IrO 2 nanoparticles on the surface. O 2 evolution of multiferroics, especially BiFeO 3 has been less investigated. Therefore, the development of efficient photocatalytic materials has relied on both photocatalysts and cocatalysts. Identification of the photogenerated charge absorption peak from transient absorption spectra facilitate the evaluation of the IrO 2 loading effect on the charge separation and the overall O 2 evolution process.
KW - BiFeO3
KW - IrO2 cocatalyst
KW - Molecular oxygen evolution
KW - Photocatalysis
KW - Transient absorption spectroscopy
UR - http://www.scopus.com/inward/record.url?scp=85114173464&partnerID=8YFLogxK
U2 - 10.1016/j.solmat.2021.111349
DO - 10.1016/j.solmat.2021.111349
M3 - Article
VL - 232
JO - Solar Energy Materials and Solar Cells
JF - Solar Energy Materials and Solar Cells
SN - 0927-0248
M1 - 111349
ER -