Atomic‐Level Dipole Engineering in Covalent Organic Frameworks for Enhancement of Photocatalytic Hydrogen Peroxide Synthesis

ABSTRACT Overcoming the fundamental challenge of rapid exciton recombination is paramount for advancing photocatalysis. Here, we introduce a paradigm‐shifting strategy based on atomic‐scale dipole engineering within covalent organic frameworks (COFs) to master charge separation. We have designed and synthesized a series of isostructural COFs incorporating different chalcogen heteroatoms (O, S, Se), systematically elucidating how electronegativity‐driven dipole polarization governs photocatalytic oxygen reduction. Under the demanding conditions of sacrificial‐agent‐free H ₂ O ₂ synthesis, the oxygen‐endowed COF (HFPB‐BO) demonstrated unparalleled performance. Attributed to its immense calculated dipole moment of 6.53 D, broad visible‐light harvesting, and the longest fluorescence lifetime in the series, HFPB‐BO achieved a remarkable H ₂ O ₂ generation rate of 2963 µmol h ⁻¹ g ⁻¹ . This rate surpasses its sulfur (HFPB‐BS) and selenium (HFPB‐BSe) analogues by factors of 1.2 and 3.1, respectively. This work establishes, for the first time, a direct and quantifiable correlation between heteroatom‐tuned dipole polarization and photocatalytic activity, presenting a rational and powerful design principle for the next generation of advanced COF photocatalysts.