Exploring the “Goldilocks Zone” of Semiconducting Polymer Photocatalysts by Donor–Acceptor Interactions

• Published in: Angewandte Chemie Vol. 130; no. 43; pp. 14384 - 14388
• Main Authors: Kochergin, Yaroslav S., Schwarz, Dana, Acharjya, Amitava, Ichangi, Arun, Kulkarni, Ranjit, Eliášová, Pavla, Vacek, Jaroslav, Schmidt, Johannes, Thomas, Arne, Bojdys, Michael J.
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 22-10-2018
• Subjects: Active sites; Catalysis; Catalytic activity; Charge transfer; Chemical synthesis; Chemistry; Chemists; Domains; Donor-Akzeptor-Systeme; Energy gap; Fluorescence; Fluoreszenzsensorik; Hydrogen-based energy; Hydrophobicity; Konjugierte mikroporöse Polymere; Optical properties; Organic chemistry; Organic compounds; Photocatalysis; Photocatalysts; Photokatalyse; Polymers; Porosity; Sulfur; Triazin; Triazine; VOCs; Volatile organic compounds; Water splitting
• ISSN: 0044-8249; 1521-3757
• DOI: 10.1002/ange.201809702

Water splitting using polymer photocatalysts is a key technology to a truly sustainable hydrogen‐based energy economy. Synthetic chemists have intuitively tried to enhance photocatalytic activity by tuning the length of π‐conjugated domains of their semiconducting polymers, but the increasing flexibility and hydrophobicity of ever‐larger organic building blocks leads to adverse effects such as structural collapse and inaccessible catalytic sites. To reach the ideal optical band gap of about 2.3 eV, A library of eight sulfur and nitrogen containing porous polymers (SNPs) with similar geometries but with optical band gaps ranging from 2.07 to 2.60 eV was synthesized using Stille coupling. These polymers combine π‐conjugated electron‐withdrawing triazine (C3N3) and electron donating, sulfur‐containing moieties as covalently bonded donor–acceptor frameworks with permanent porosity. The remarkable optical properties of SNPs enable fluorescence on‐off sensing of volatile organic compounds and illustrate intrinsic charge‐transfer effects.
Das passt! Eine Bibliothek von acht hoch modularen, photoaktiven S‐ und N‐haltigen porösen Polymeren (SNPs) ermöglichte die Erforschung der idealen Bedingungen für photokatalytische Wasserspaltung. Intrinsische Push‐pull‐Effekte führten zur verbesserten Trennung von photoinduzierten Ladungsträgern und zu einer feinen Abstimmbarkeit der Bandlücke, wodurch Materialien mit der höchsten bisher berichteten Wasserstoffentwicklungsrate erhalten wurden.