Title data
Schwinghammer, Katharina ; Hug, Stephan ; Mesch, Maria B. ; Senker, Jürgen ; Lotsch, Bettina V.:
Phenyl-Triazine Oligomers for Light-Driven Hydrogen Evolution.
In: Energy & Environmental Science.
Vol. 8
(2015)
Issue 11
.
- pp. 3345-3353.
ISSN 1754-5706
DOI: https://doi.org/10.1039/c5ee02574e
Abstract in another language
The design of stable, yet highly tunable organic photocatalysts which orchestrate multi-step electron transfer reactions is at the heart of the newly emerging field of polymer photocatalysis. Covalent triazine frameworks such as the archetypal CTF-1 have been theorized to constitute a new class of photocatalytically active polymers for light-driven water splitting. Here, we revisit the ionothermal synthesis of CTF-1 by trimerization of 1,4-dicyanobenzene catalyzed by the Lewis acid zinc chloride and demonstrate that the microporous black polymer CTF-1 is essentially inactive for hydrogen evolution. Instead, highly photoactive phenyl-triazine oligomers (PTOs) with higher crystallinity as compared to CTF-1 are obtained by lowering the reaction temperature to 300 degrees C and prolonging the reaction time to 4150 hours. The low reaction temperature of the PTOs largely prevents incipient carbonization and thus results in a carbon-to-nitrogen weight ratio close to the theoretical value of 3.43. The oligomers were characterized by MALDI-TOF and quantitative solid-state NMR spectroscopy, revealing variations in size, connectivity and thus nitrile-to-triazine ratios depending on the initial precursor dilution. The most active PTO samples efficiently and stably reduce water to hydrogen with an average rate of 1076 (+/- 278) mmol h(-1) g(-1) under simulated sunlight illumination, which is competitive with the best carbon nitride-based and purely organic photocatalysts. The photocatalytic activity of the PTOs is found to sensitively depend on the polymerization degree, thus suggesting a prominent role of the unreacted nitrile moieties in the photocatalytic process. Notably, PTOs even show moderate hydrogen production without the addition of any co-catalyst.
Further data
Item Type: | Article in a journal |
---|---|
Refereed: | Yes |
Institutions of the University: | Faculties > Faculty of Biology, Chemistry and Earth Sciences > Department of Chemistry > Chair Inorganic Chemistry III > Chair Inorganic Chemistry III - Univ.-Prof. Dr. Jürgen Senker Faculties Faculties > Faculty of Biology, Chemistry and Earth Sciences Faculties > Faculty of Biology, Chemistry and Earth Sciences > Department of Chemistry Faculties > Faculty of Biology, Chemistry and Earth Sciences > Department of Chemistry > Chair Inorganic Chemistry III |
Result of work at the UBT: | No |
DDC Subjects: | 500 Science > 540 Chemistry |
Date Deposited: | 26 Jul 2016 12:17 |
Last Modified: | 25 Mar 2024 08:00 |
URI: | https://eref.uni-bayreuth.de/id/eprint/33643 |