Pyridine‐Based Covalent Organic Frameworks with Pyridyl‐Imine Structures for Boosting Photocatalytic H₂O₂ Production via One‐Step 2e⁻ Oxygen Reduction

Abstract

Abstract Bipyridine‐based covalent organic frameworks (COFs) have emerged as promising contenders for the photocatalytic generation of hydrogen peroxide (H 2 O 2 ). However, the presence of imine nitrogen alters the mode of H 2 O 2 generation from an efficient one‐step two‐electron (2e − ) route to a two‐step 2e − oxygen reduction pathway. In this work, we introduce 3,3′‐bipyridine units into imine‐based COF skeletons, creating a pyridyl‐imine structure with two adjacent nitrogen atoms between the pyridine ring and imine linkage. This unique bipyridine‐like architecture can effectively suppress the two‐step 2e − ORR process at the single imine‐nitrogen site, facilitating a more efficient one‐step 2e − pathway. Consequently, the optimized pyridyl‐imine COF (PyIm‐COF) exhibits a remarkable H 2 O 2 production rate of up to 5850 μmol h −1 g −1 , nearly double that of pristine bipyridine COFs. This work provides valuable insight into the rational design of functionalized COFs for enhanced H 2 O 2 production in photocatalysis.