Hydrophobic covalent organic frameworks utilized Fluorocarbon/Water system for efficient hydrogen peroxide photosynthesis

Great efforts have been made for H2O2 production by an artificial photosynthetic approach. However, the poor solubility of oxygen in the liquid phase, sluggish mass transfer, and additional concentration step to produce H2O2 have limited the development of this technology. Herein, a unique fluorocarbon/hydrophobic photocatalysts/water system is reported, which ensures an efficient photosynthesis and spontaneous self-separation of H2O2. The presence of an ultra-thin dense gas layer between the perfluorous solvent and the photocatalysts enables rapid oxygen supply through a nano-confinement effect. Thus, a maximum photosynthetic efficiency of 4.9 mM g−1h−1 of H2O2 is achieved, 6 times higher compared to its counterpart gas–liquid-solid triphase system. Importantly, the independent hierarchical structure of the present system, allows functional applications, such as the Fenton reaction using pre-added Fe2+ in the aqueous solution. This feature makes the fluorocarbon/water systems is an advantageous one and of extraordinary significance for similar types of gas–liquid reactions.