Three-Component Vinylene-Linked Donor–Acceptor-Type Organic Semiconductive Covalent Organic Frameworks for Efficient Sunlight-Driven Hydrogen Evolution Reaction

High Resolution Image Download MS PowerPoint Slide Continuous electron donor–acceptor covalent organic frameworks ( D–A COFs ) could serve as ideal platforms to investigate the correlation between the structures of organic polymers and their photocatalytic efficiency. In this report, we present a study on the correlation of the structures of D–A COFs with their catalytic efficiency. The two D–A COFs, COF-1 and COF-2, which structurally incorporate triazine and thiophene units linked by a vinylene bridge, were synthesized via a three-component Knoevenagel condensation reaction. The benzotrithiophene-based COF-1 exhibited superior optical and photoelectrical properties compared with the 1,3,5-tri(thiophen-2-yl)benzene-based COF-2 . COF-1 and COF-2 demonstrated impressive photocatalytic hydrogen evolution reaction (HER) rates of approximately 69.1 and 56.6 mmol/g/h, respectively. The superior photocatalytic performance of COF-1 compared with that of COF-2 can be attributed to the distinct structural features of the benzotrithiophene and 1,3,5-tri(thiophen-2-yl)benzene units within the frameworks.