Einert, Marcus ; Waheed, Arslan ; Moritz, Dominik C. ; Lauterbach, Stefan ; Kundmann, Anna ; Daemi, Sahar ; Schlaad, Helmut ; Osterloh, Frank E. ; Hofmann, Jan P. (2023)
Mesoporous CuFe₂O₄ Photoanodes for Solar Water Oxidation: Impact of Surface Morphology on the Photoelectrochemical Properties.
In: Chemistry – A European Journal, 29 (24)
doi: 10.1002/chem.202300277
Artikel, Bibliographie
Dies ist die neueste Version dieses Eintrags.
Kurzbeschreibung (Abstract)
Metal oxide‐based photoelectrodes for solar water splitting often utilize nanostructures to increase the solid‐liquid interface area. This reduces charge transport distances and increases the photocurrent for materials with short minority charge carrier diffusion lengths. While the merits of nanostructuring are well established, the effect of surface order on the photocurrent and carrier recombination has not yet received much attention in the literature. To evaluate the impact of pore ordering on the photoelectrochemical properties, mesoporous CuFe₂O₄ (CFO) thin film photoanodes were prepared by dip‐coating and soft‐templating. Here, the pore order and geometry can be controlled by addition of copolymer surfactants poly(ethylene oxide)‐block‐poly(propylene oxide)‐block‐poly(ethylene oxide) (Pluronic® F‐127), polyisobutylene‐block‐poly(ethylene oxide) (PIB‐PEO) and poly(ethylene‐co‐butylene)‐block‐poly(ethylene oxide) (Kraton liquid™‐PEO, KLE). The non‐ordered CFO showed the highest photocurrent density of 0.2 mA/cm² at 1.3 V vs. RHE for sulfite oxidation, but the least photocurrent density for water oxidation. Conversely, the ordered CFO presented the best photoelectrochemical water oxidation performance. These differences can be understood on the basis of the high surface area, which promotes hole transfer to sulfite (a fast hole acceptor), but retards oxidation of water (a slow hole acceptor) due to electron‐hole recombination at the defective surface. This interpretation is confirmed by intensity‐modulated photocurrent (IMPS) and vibrating Kelvin probe surface photovoltage spectroscopy (VKP‐SPS). The lowest surface recombination rate was observed for the ordered KLE‐based mesoporous CFO, which retains spherical pore shapes at the surface resulting in fewer surface defects. Overall, this work shows that the photoelectrochemical energy conversion efficiency of copper ferrite thin films is not just controlled by the surface area, but also by surface order.
| Typ des Eintrags: | Artikel |
|---|---|
| Erschienen: | 2023 |
| Autor(en): | Einert, Marcus ; Waheed, Arslan ; Moritz, Dominik C. ; Lauterbach, Stefan ; Kundmann, Anna ; Daemi, Sahar ; Schlaad, Helmut ; Osterloh, Frank E. ; Hofmann, Jan P. |
| Art des Eintrags: | Bibliographie |
| Titel: | Mesoporous CuFe₂O₄ Photoanodes for Solar Water Oxidation: Impact of Surface Morphology on the Photoelectrochemical Properties |
| Sprache: | Englisch |
| Publikationsjahr: | 2023 |
| Ort: | Darmstadt |
| Verlag: | Wiley-VCH |
| Titel der Zeitschrift, Zeitung oder Schriftenreihe: | Chemistry – A European Journal |
| Jahrgang/Volume einer Zeitschrift: | 29 |
| (Heft-)Nummer: | 24 |
| Kollation: | 16 Seiten |
| DOI: | 10.1002/chem.202300277 |
| Zugehörige Links: | |
| Kurzbeschreibung (Abstract): | Metal oxide‐based photoelectrodes for solar water splitting often utilize nanostructures to increase the solid‐liquid interface area. This reduces charge transport distances and increases the photocurrent for materials with short minority charge carrier diffusion lengths. While the merits of nanostructuring are well established, the effect of surface order on the photocurrent and carrier recombination has not yet received much attention in the literature. To evaluate the impact of pore ordering on the photoelectrochemical properties, mesoporous CuFe₂O₄ (CFO) thin film photoanodes were prepared by dip‐coating and soft‐templating. Here, the pore order and geometry can be controlled by addition of copolymer surfactants poly(ethylene oxide)‐block‐poly(propylene oxide)‐block‐poly(ethylene oxide) (Pluronic® F‐127), polyisobutylene‐block‐poly(ethylene oxide) (PIB‐PEO) and poly(ethylene‐co‐butylene)‐block‐poly(ethylene oxide) (Kraton liquid™‐PEO, KLE). The non‐ordered CFO showed the highest photocurrent density of 0.2 mA/cm² at 1.3 V vs. RHE for sulfite oxidation, but the least photocurrent density for water oxidation. Conversely, the ordered CFO presented the best photoelectrochemical water oxidation performance. These differences can be understood on the basis of the high surface area, which promotes hole transfer to sulfite (a fast hole acceptor), but retards oxidation of water (a slow hole acceptor) due to electron‐hole recombination at the defective surface. This interpretation is confirmed by intensity‐modulated photocurrent (IMPS) and vibrating Kelvin probe surface photovoltage spectroscopy (VKP‐SPS). The lowest surface recombination rate was observed for the ordered KLE‐based mesoporous CFO, which retains spherical pore shapes at the surface resulting in fewer surface defects. Overall, this work shows that the photoelectrochemical energy conversion efficiency of copper ferrite thin films is not just controlled by the surface area, but also by surface order. |
| Freie Schlagworte: | mesoporous thin-films, photoelectrochemistry, sol-gel, water oxidation |
| ID-Nummer: | e202300277 |
| Zusätzliche Informationen: | A previous version of this manuscript has been deposited on a preprint server (https://doi.org/10.26434/chemrxiv-2022-txgvp). |
| Sachgruppe der Dewey Dezimalklassifikatin (DDC): | 600 Technik, Medizin, angewandte Wissenschaften > 660 Technische Chemie |
| Fachbereich(e)/-gebiet(e): | 11 Fachbereich Material- und Geowissenschaften 11 Fachbereich Material- und Geowissenschaften > Geowissenschaften 11 Fachbereich Material- und Geowissenschaften > Geowissenschaften > Fachgebiet Geomaterialwissenschaft 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft > Fachgebiet Oberflächenforschung |
| Hinterlegungsdatum: | 02 Aug 2024 12:54 |
| Letzte Änderung: | 02 Aug 2024 12:54 |
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Verfügbare Versionen dieses Eintrags
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Mesoporous CuFe₂O₄ Photoanodes for Solar Water Oxidation: Impact of Surface Morphology on the Photoelectrochemical Properties. (deposited 04 Aug 2023 12:32)
- Mesoporous CuFe₂O₄ Photoanodes for Solar Water Oxidation: Impact of Surface Morphology on the Photoelectrochemical Properties. (deposited 02 Aug 2024 12:54) [Gegenwärtig angezeigt]
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