A Hydrogen Bonded Organic Framework Constructed from Mixed Valence Fe Clusters for Efficient H2O2 Photosynthesis

Abstract

A critical bottleneck in photocatalytic H2O2 production lies not only in the severe non-radiative energy losses incurred from enhancing light absorption, but also in a fundamental proton-electron kinetic imbalance. Here we introduce a light–heat–proton coupling strategy that harnesses the dissipated photothermal energy to activate proton dissociation from carboxylic acids, thereby creating a productive driving force for redox catalysis. A hydrogen-bonded organic framework (HOF-FJU-200) incorporating mixed-valence Fe2+/Fe3+ clusters is constructed via a metalloligand approach. The intervalence charge transfer transitions within these clusters generate strong photothermal conversion while extending light absorption to the NIR-II region ( ~ 2500 nm). The resulting thermal energy activates proton dissociation from unpaired carboxylic acid groups, synchronizing proton release with photoinduced electron transfer. This cooperative mechanism effectively channels non-radiative heat into catalytic function, achieving an H2O2 production rate of 10657 μmol·g−1·h−1 without sacrificial agents. By directly coupling light, heat, and proton dynamics within a single framework, this work establishes a general paradigm for utilizing non-radiative energy to regulate proton-driven photocatalytic reactions. Photocatalytic H₂O₂ production is limited not only by severe non-radiative energy losses but also by a fundamental imbalance between proton and electron transfer kinetics. Here, the authors develop a light–heat–proton coupling strategy that exploits dissipated photothermal energy to promote proton dissociation from carboxylic acids, creating a driving force for efficient redox catalysis and H₂O₂ generation.