Enhanced Photocatalytic H ₂ O ₂ Production on Terpyridine‐Based Acrylonitrile‐Linked Covalent Organic Frameworks with Asymmetric Localized Electron Distribution

Abstract

ABSTRACT Covalent organic frameworks (COFs) serve as promising photocatalysts for sustainable photosynthesis of H 2 O 2 from water and air due to their well‐defined architecture and precisely controllable structure. The key to achieving high H 2 O 2 production rates lies in the efficient adsorption of O 2 and effective charge transfer over COFs. In this work, we have studied a terpyridine‐based acrylonitrile‐linked COF (TPy‐acr COF) with optimum localized electron distribution and enhanced charge transfer for two‐electron transfer oxygen reduction toward H 2 O 2 production. The electron‐deficient pyridine nitrogen atoms in the terpyridine unit induce an asymmetric electron distribution with localized electron density at the adjacent carbon atoms, while the electron‐withdrawing acrylonitrile linkage increases the electron distribution asymmetry of the entire framework. Consequently, the high electron‐density carbon atoms in the terpyridine units of TPy‐acr COF show strong binding for O 2 and fast charge transfer to the key intermediate * OOH. Remarkably, the TPy‐acr COF enabled a high production rate of 4.85 mmol g −1 h −1 for H 2 O 2 directly from water and air. An outdoor scale‐up experiment shows an average H 2 O 2 production rate of 1.14 mmol g −1 h −1 over TPy‐acr COF using water in ambient air under natural sunlight, demonstrating practical application potential with sustainability, simplicity, and scalability.