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A Study in Red: The Overlooked Role of Azo‐Moieties in Polymeric Carbon Nitride Photocatalysts with Strongly Extended Optical Absorption

Mitoraj, Dariusz; Krivtsov, Igor; Li, Chunyu; Rajagopal, Ashwene; Im, Changbin; Adler, Christiane; Köble, Kerstin; Khainakova, Olena; Hniopek, Julian; Neumann, Christof; Turchanin, Andrey; Silva, Ivan; Schmitt, Michael; Leiter, Robert; Lehnert, Tibor; Popp, Jürgen; Kaiser, Ute; Jacob, Timo; Streb, Carsten; ... mehr


The unique optical and photoredox properties of heptazine-based polymeric carbon nitride (PCN) materials make them promising semiconductors for driving various productive photocatalytic conversions. However, their typical absorption onset at ca. 430–450 nm is still far from optimum for efficient sunlight harvesting. Despite many reports of successful attempts to extend the light absorption range of PCNs, the determination of the structural features responsible for the red shift of the light absorption edge beyond 450 nm has often been obstructed by the highly disordered structure of PCNs and/or low content of the moieties responsible for changes in optical and electronic properties. In this work, we implement a high-temperature (900 °C) treatment procedure for turning the conventional melamine-derived yellow PCN into a red carbon nitride. This approach preserves the typical PCN structure but incorporates a new functionality that promotes visible light absorption. A detailed characterization of the prepared material reveals that partial heptazine fragmentation accompanied by de-ammonification leads to the formation of azo-groups in the red PCN, a chromophore moiety whose role in shifting the optical absorption edge of PCNs has been overlooked so far. ... mehr

Verlagsausgabe §
DOI: 10.5445/IR/1000142456
Veröffentlicht am 26.01.2022
DOI: 10.1002/chem.202102945
Zitationen: 2
Web of Science
Zitationen: 1
Zitationen: 2
Cover der Publikation
Zugehörige Institution(en) am KIT Helmholtz-Institut Ulm (HIU)
Publikationstyp Zeitschriftenaufsatz
Publikationsdatum 06.12.2021
Sprache Englisch
Identifikator ISSN: 0947-6539, 1521-3765
KITopen-ID: 1000142456
HGF-Programm 38.02.01 (POF IV, LK 01) Fundamentals and Materials
Erschienen in Chemistry - a European journal
Verlag John Wiley and Sons
Band 27
Heft 68
Seiten 17188–17202
Bemerkung zur Veröffentlichung Special Issue: Contemporary Challenges in Catalysis
Vorab online veröffentlicht am 29.09.2021
Nachgewiesen in Dimensions
Web of Science
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