Gradient‐Polarized COFs for Paired H 2 O 2 /Imine Photosynthesis

ABSTRACT Photocatalytic hydrogen peroxide (H 2 O 2 ) synthesis coupled with organic oxidation offers an efficient approach for solar‐to‐chemical conversion but is limited by inefficient charge separation and mismatched redox kinetics. We present a gradient‐polarized covalent organic framework (COF) platform, achieved by strengthening benzothiadiazole‐based acceptor units along a conjugated donor backbone. This gradient polarization creates a directional charge‐migration field, enhancing exciton dissociation and synchronizing electron–proton utilization in paired redox reactions. Optimized BTD‐BTT‐COF exhibits a high H 2 O 2 production rate of 25.67 mmolg ‒1 h ‒1 (AQY = 18.4%), achieving nearly quantitative benzylamine‐to‐imine conversion (>99% yield, >99.9% selectivity), and excellent stability. Spectroscopic analysis, isotopic labeling, and DFT calculations show that gradient polarization suppresses charge recombination and promotes electron accumulation at thiadiazole‐rich regions, enhancing oxygen activation, stabilizing superoxide and *OOH intermediates, and lowering the kinetic barrier of the ORR pathway. Coupled benzylamine (BnAm) oxidation further extracts holes and supplies protons for proton‐coupled electron transfer, amplifying catalytic turnover. This work establishes gradient polarization as a general design principle for COF photocatalysts, enabling efficient charge and reaction kinetics regulation in paired photosynthetic systems.