Redox‐Mediated TEMPO‐based D‐A Covalent Organic Framework for Efficient Photo‐Induced Hydrogen Peroxide Generation

Molecular engineering of covalent organic frameworks (COFs) offers an alternative approach to conventional anthraquinone oxidation via photo‐induced H2O2 production from O2 reduction. Despite their potential, reported photocatalysts suffer limited proton mobility, low selectivity, and insufficient charge separation and utilization. Herein, we report a nitroxyl radical (TEMPO) decorated two‐dimensional (2D) donor‐acceptor (D‐A)‐COF photocatalyst via a one‐pot strategy linking the porphyrin unit. Under visible light irradiation, highly crystalline TAPP‐TPDA‐TEMPO‐COF (TT‐T‐COF) exhibits a remarkable photocatalytic H2O2 yield of 10066 μmol g−1 h−1 in two‐phase water‐benzyl alcohol (BA 10%) system through direct two‐electron (2e−) pathway. The mechanistic study by DFT calculations and in‐situ DRIFT spectra suggests Yeager‐type adsorption of O2 on the nitroxyl radical site (N‐O•). The efficient photocatalytic performance and stability of TT‐T‐COF are attributed to the involvement of the nitroxyl radical (N‐O•), which enhances selective O2 adsorption, establishes a distinct electron density distribution, and facilitates photogenerated charge carrier (electron‐hole) separation compared to TT‐HT‐COF and TT‐COF counterparts. This study uncovers a new perspective for constructing metal‐free, redox‐mediated radical‐based COFs for sustainable energy conversion, storage, and biomedical applications.