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

Abstract

Abstract Photocatalytic oxygen reduction to produce hydrogen peroxide (H 2 O 2 ) is a promising route to providing oxidants for various industrial applications. However, the lack of well‐designed photocatalysts for efficient overall H 2 O 2 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 H 2 O 2 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 *O 2 ⋅ − intermediate in the cyanide active site, which prohibits the formation of superoxide radical and revealing a favored H 2 O 2 production pathway.