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Abstract Metal‐Organic Frameworks (MOFs) recently emerged as a new platform for the realization of integrated devices for artificial photosynthesis. However, there remain few demonstrations of rational tuning of such devices for improved performance. Here, a fast molecular water oxidation catalyst working via water nucleophilic attack is integrated into the MOF MIL‐142, wherein Fe3O nodes absorb visible light, leading to charge separation. Materials are characterized by a range of structural and spectroscopic techniques. New, [Ru(tpy)(Qc)(H2O)]+(tpy = 2,2′:6′,2″‐terpyridine and Qc = 8‐quinolinecarboxylate)‐doped Fe MIL‐142 achieved a high photocurrent (1.6 × 10−3A·cm−2) in photo‐electrocatalytic water splitting at pH = 1. Unassisted photocatalytic H2evolution is also reported with Pt as the co‐catalyst (4.8 µmol g−1min−1). The high activity of this new system enables hydrogen gas capture from an easy‐to‐manufacture, scaled‐up prototype utilizing MOF deposited on FTO glass as a photoanode. These findings provide insights for the development of MOF‐based light‐driven water‐splitting assemblies utilizing a minimal amount of precious metals and Fe‐based photosensitizers.
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Fe‐Triazolate Metal–Organic Frameworks as Water Oxidation Catalysts with Dual Photoanode Functionality
Abstract Artificial photosynthesis is an emerging technology that achieves renewable fuels, such as hydrogen, from sunlight. Its realization depends on finding highly active and stable catalysts of water splitting and photoactive materials for light absorption. To be scalable, these should contain only abundant elements. Here, for the first time, Fe‐triazolate (Fe(ta)2) and its metal substituted derivatives (Fe‐Metal(ta)2) Metal‐organic frameworks (MOFs) are characterized as new dual‐function materials for photo‐absorption and water oxidation catalysis in acidic media. The materials were studied by a range of structural, spectroscopic, and computational density functional theory (DFT) techniques. Fe(ta)2and Fe‐Mn(ta)2were found to be highly active and stable in chemical and photochemical water oxidation, and in addition function as photoanodes, with photo‐electrocatalytic currents (∼2.00 x 10−3Acm−2at + 1.4 V vs. Ag/AgCl) atpH = 1. The possibility of a unique catalytic mechanism where O─O bond formation is possible from the coupling of two adjacent FeIV = O fragments was demonstrated by DFT analysis. Thus, Fe‐triazolate MOF has been established as a new, stable, scalable, versatile, and efficient platform for sustainable energy conversion in the realm of artificial photosynthesis.
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- Award ID(s):
- 2155060
- PAR ID:
- 10642846
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Angewandte Chemie
- Volume:
- 137
- Issue:
- 40
- ISSN:
- 0044-8249
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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