Engineering intermolecular C-F···C=O interactions in covalent organic framework promotes dual-path H₂O₂...

The urgent need to address the high prevalence of waterborne diseases in underdeveloped regions necessitates the development of economically viable, decentralized, and sunlight-assisted disinfection techniques. An encouraging solution lies in the utilization of photosynthesized H₂O₂ to initiate advanced oxidation processes (AOPs). However, challenges persist in the quest to develop efficient photocatalysts and reactor designs. Herein, we present the rational design and synthesis of a metal-free supramolecular photocatalyst achieved via the post-functionalization of fluorine-substituted covalent organic frameworks (FCOFs) with polyvinylpyrrolidone (PVP). The resulting FCOF/PVP composite establishes intermolecular C-F···C=O interactions at the interface, which facilitate accelerated charge separation and transfer, as well as promote efficient intersystem crossing to enhance the formation of molecular triplet excitons. These photophysical enhancements enable dual-pathway H₂O₂ generation mediated by superoxide radicals (•O₂^-) and singlet oxygen (¹O₂), yielding a H₂O₂ production rate of 1763.50 μmol/g/h from pure water and atmospheric oxygen. The photosynthesized H₂O₂ is subsequently catalyzed by Fe(II) to generate hydroxyl radicals (•OH), achieving effective inactivation of pathogenic bacteria and viruses. A continuous-flow system was further developed to couple photocatalytic H₂O₂ production with Fenton disinfection, combining the benefits of heterogeneous and homogeneous catalysis while addressing limitations in photocatalyst recovery and light dependency. This system exhibited robust disinfection performance under real water matrices and intermittent light conditions. Economic analysis supports the feasibility of the system for deployment in resource-limited settings, offering a novel material-based approach for decentralized water treatment and global efforts to mitigate waterborne diseases.