Perfluoroalkyl-modified covalent organic frameworks for continuous photocatalytic hydrogen peroxide synthesis and extraction in a biphasic fluid system

H₂O₂ photosynthesis represents an appealing approach for sustainable and decentralized H₂O₂ production. Unfortunately, current reactions are mostly carried out in laboratory-scale single-phase batch reactors, which have a limited H₂O₂ production rate (<100 μmol h^-1) and cannot operate in an uninterrupted manner. Herein, we propose continuous H₂O₂ photosynthesis and extraction in a biphasic fluid system. A superhydrophobic covalent organic framework photocatalyst with perfluoroalkyl functionalization is rationally designed and prepared via the Schiff-base reaction. When applied in a home-built biphasic fluid photo-reactor, the superhydrophobicity of our photocatalyst allows its selective dispersion in the oil phase, while formed H₂O₂ is spontaneously extracted to the water phase. Through optimizing reaction parameters, we achieve continuous H₂O₂ photosynthesis and extraction with an unprecedented production rate of up to 968 μmol h^-1 and tunable H₂O₂ concentrations from 2.2 to 38.1 mM. As-obtained H₂O₂ solution could satisfactorily meet the general demands of household disinfection and wastewater treatments.