at Google ScholarTitle data
Schlomberg, Hendrik ; Kroeger, Julia ; Savasci, Gökcen ; Terban, Maxwell W. ; Bette, Sebastian ; Moudrakovski, Igor ; Duppel, Viola ; Podjaski, Filip ; Siegel, Renée ; Senker, Jürgen ; Dinnebier, Robert E. ; Ochsenfeld, Christian ; Lotsch, Bettina V.:
Structural Insights into Poly(Heptazine Imides): a Light-Storing Carbon Nitride Material for Dark Photocatalysis.
In: Chemistry of Materials.
Vol. 31
(2019)
Issue 18
.
- pp. 7478-7486.
ISSN 1520-5002
DOI: https://doi.org/10.1021/acs.chemmater.9b02199
Abstract in another language
Solving the structure of carbon nitrides has been a long-standing challenge due to the low crystallinity and complex structures observed within this class of earth-abundant photocatalysts. Herein, we report on two-dimensional layered potassium poly(heptazine imide) (K-PHI) and its proton-exchanged counterpart (H-PHI), obtained by ionothermal synthesis using a molecular precursor route. We present a comprehensive analysis of the in-plane and three-dimensional structure of PHI. Transmission electron microscopy and solid-state NMR spectroscopy, supported by quantum-chemical calculations, suggest a planar, imide-bridged heptazine backbone with trigonal symmetry in both K-PHI and H-PHI, whereas pair distribution function analyses and X-ray powder diffraction using recursive-like simulations of planar defects point to a structure-directing function of the pore content. While the out-of-plane structure of K-PHI exhibits a unidirectional layer offset, mediated by hydrated potassium ions, H-PHI is characterized by a high degree of stacking faults due to the weaker structure directing influence of pore water. Structure-property relationships in PHI reveal that a loss of in-plane coherence, materializing in smaller lateral platelet dimensions and increased terminal cyanamide groups, correlates with improved photocatalytic performance. Size-optimized H-PHI is highly active toward photocatalytic hydrogen evolution, with a rate of 3363 mu mol/gh H-2 placing it on par with the most active carbon nitrides. K- and H-PHI adopt a uniquely long-lived photoreduced polaronic state in which light-induced electrons are stored for more than 6 h in the dark and released upon addition of a Pt cocatalyst. This work highlights the importance of structure- property relationships in carbon nitrides for the rational design of highly active hydrogen evolution photocatalysts.
Further data
| Item Type: | Article in a journal |
|---|---|
| Refereed: | Yes |
| Additional notes: | ISI:000487859200041 |
| Institutions of the University: | 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 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 |
| Result of work at the UBT: | Yes |
| DDC Subjects: | 500 Science 500 Science > 540 Chemistry |
| Date Deposited: | 15 Nov 2019 11:05 |
| Last Modified: | 11 May 2022 13:41 |
| URI: | https://eref.uni-bayreuth.de/id/eprint/53235 |