Interfacial design of pyrene-based covalent organic framework for overall photocatalytic HO synthesis in water.

Covalent organic frameworks (COFs) have shown great potential in the photocatalytic production of hydrogen peroxide (HO) due to their precisely designed and customized ability. Nevertheless, the quest for efficient overall photosynthesis of HO in pure water without sacrificial agents using COF photocatalysts remains a formidable challenge. Herein, three pyrene-based covalent organic frameworks are synthesized using an advanced interfacial design strategy. By incorporating functional groups of F, H, and OH into a COF skeleton, their wettability and charge-separation properties are fine-tuned. These COFs show great performances as photocatalysts for HO production from water and air by utilizing both the oxygen reduction reaction and water oxidation reaction pathways. Compared to PyCOF-F and PyCOF-H, PyCOF-OH demonstrates superior HO production efficiency due to its improved hydrophilicity and enhanced carrier separation, achieving a remarkable rate of 2961 µmol g h from 25 mL pure water and air. Further, the mechanism of HO production over PyCOF-OH is clarified by combining a series of control experiments, in situ characterizations, and theoretical calculations. This study offers valuable insights into the interfacial design of high-performance photocatalysts for HO synthesis.