Tunable Isometric Donor‐Acceptor Wurster‐Type Covalent Organic Framework Photocathodes

Guntermann, Roman ; Helminger, David; Frey, Laura ; Zehetmaier, Peter M.; Wangnick, Christian; Singh, Apeksha ; Xue, Tianhao ; Medina, Dana D. und Bein, Thomas (2024): Tunable Isometric Donor‐Acceptor Wurster‐Type Covalent Organic Framework Photocathodes. In: Angewandte Chemie International Edition

Abstract

Covalent organic frameworks (COFs) offer remarkable versatility, combining ordered structures, high porosity, and tailorable functionalities in nanoscale reaction spaces. Herein, we report the synthesis of a series of isostructural, photoactive Wurster-type COFs achieved by manipulating the chemical and electronic nature of the Wurster aromatic amine building blocks. A series of donor-acceptor-donor (D-A-D) Wurster building block molecules was synthesized by incorporating heteroaromatic acceptors with varying strengths between triphenylamine donor groups. These tailored building blocks were integrated into a 2D COF scaffold, resulting in highly crystalline structures and similar morphologies across all COFs. Remarkably, this structural uniformity was also achieved in the synthesis of homogeneous and oriented thin films. Steady-state photoluminescence revealed a tunable red-shift in film emission exceeding 100 nm, demonstrating effective manipulation of their optical properties. Furthermore, photoelectrochemical (PEC) water splitting studies exhibited a doubled current density (8.1 μA cm−2 at 0.2 VRHE) for the COF with the strongest acceptor unit. These findings highlight the potential of Wurster D-A-D COFs in photoelectrochemical water splitting devices and pave the way for further exploration of chemical functionality-reactivity-property relationships in this promising class of photoactive materials.

• Dokumententyp: Zeitschriftenartikel
• Fakultätsübergreifende Einrichtungen: Center for NanoScience (CENS)
• Themengebiete: 500 Naturwissenschaften und Mathematik > 540 Chemie
• ISSN: 1433-7851
• Sprache: Englisch
• DFG: Gefördert durch die Deutsche Forschungsgemeinschaft (DFG) - 390776260