KIT | KIT-Bibliothek | Impressum | Datenschutz

Structure and Optical Properties of Polymeric Carbon Nitrides from Atomistic Simulations

Im, Changbin; Kirchhoff, Björn; Krivtsov, Igor; Mitoraj, Dariusz; Beranek, Radim; Jacob, Timo 1
1 Helmholtz-Institut Ulm (HIU), Karlsruher Institut für Technologie (KIT)


Detailed understanding of the structural and photophysical properties of polymeric carbon nitride (PCN) materials is of critical importance to derive future material optimization strategies towards more desirable optical properties and more photocatalytically active materials. However, the wide range of structural motifs found in synthesized PCNs complicates atomistic simulations that rely on well defined models. Performing hybrid DFT studies, we systematically investigate formation energy trends and optical properties of PCNs as a function of dimensionality, going from molecular oligomers over periodic sheet models to stacked crystals. Thermochemical calculations that take into account vibrational enthalpy and entropy contributions predict that a mixture of structural motifs including the melon string structure, poly(heptazine imide), and g-C3N4 motifs is stable under typical synthetic conditions. The degree of lateral condensation as well as stacking can reduce the bandgap while out-of-plane corrugation of the material increases both stability and the optical gap. The key result of this work is that already small domains of strongly condensed PCN are calculated to give rise to favorable optical properties. ... mehr

Volltext §
DOI: 10.5445/IR/1000156545
Veröffentlicht am 08.03.2023
Cover der Publikation
Zugehörige Institution(en) am KIT Helmholtz-Institut Ulm (HIU)
Publikationstyp Forschungsbericht/Preprint
Publikationsjahr 2022
Sprache Englisch
Identifikator KITopen-ID: 1000156545
Umfang 47 S.
Vorab online veröffentlicht am 04.08.2022
Nachgewiesen in arXiv
Relationen in KITopen
KIT – Die Forschungsuniversität in der Helmholtz-Gemeinschaft
KITopen Landing Page