Oligo(Phenylenevinylene)-Based Covalent Organic Frameworks with Kagome Lattice For Boosting Photocatalytic Hydrogen Evolution.

Covalent organic frameworks (COFs) have shown great advantages as photocatalysts for hydrogen evolution. However, the effect of linkage geometry and type of linkage on the extent of π-electron conjugation in the plane of the framework and photocatalytic properties of COFs remains a significant challenge. Herein, we design and synthesize two kgm topologic oligo(phenylenevinylene)-based COFs for boosting photocatalytic hydrogen evolution via a "two in one" strategy. Under visible light irradiation, COF-954 with 5 wt% Pt as cocatalyst exhibit high hydrogen evolution rate (HER) of 137.23 mmol g -1 h -1 , outperforming most reported COF-based photocatalysts. More importantly, even in natural seawater, COF-954 shows an average HER of 191.70 mmol g -1 h -1 under ultraviolet-visible light irradiation. Additionally, the water-drainage experiments indoors and outdoors demonstrate that 25 mL and 8 mL hydrogen gas could be produced in 80 mins under ultraviolet-visible light and natural sunlight, respectively, corresponding to a high HER of 167.41 and 53.57 mmol h -1 g -1 . This work not only demonstrate an effective design strategy towards highly efficient COF-based photocatalysts, but also shows the great potential of using the COF-based photocatalysts for photocatalytic hydrogen evolution. This article is protected by copyright. All rights reserved.