Cyanide‐based Covalent Organic Frameworks for Enhanced Overall Photocatalytic Hydrogen Peroxide Production.

Photocatalytic oxygen reduction to produce hydrogen peroxide (H2O2) is a promising route to providing oxidants for various industrial applications. However, the lack of well‐designed photocatalysts for efficient overall H2O2 production in pure water has impeded ongoing research and practical thrusts. Here we present a cyanide‐based covalent organic framework (TBTN‐COFs) combining 2,4,6‐trimethylbenzene‐1,3,5‐tricarbonitrile (TBTN) and benzotrithiophene‐2,5,8‐tricarbaldehyde (BTT) building blocks with water‐affinity and charge‐separation. The ultrafast intramolecular electron transfer (<500 fs) and prolonged excited state lifetime (748 ps) can be realized by TBTN‐COF, resulting in a hole accumulated BTT and electron‐rich TBTN building block. Under one sun, the 11013 μmol h−1 g−1 yield rate of H2O2 can be achieved without any sacrificial agent, outperforming most previous reports. Furthermore, the DFT calculation and in situ DRIFTS spectrums suggesting a Yeager‐type absorption of *O2⋅− intermediate in the cyanide active site, which prohibits the formation of superoxide radical and revealing a favored H2O2 production pathway. [ABSTRACT FROM AUTHOR]