Molecularly Engineered Covalent Organic Frameworks for Hydrogen Peroxide Photosynthesis
Mingpu Kou, Yongye Wang, Yixue Xu, Liqun Ye, Yingping Huang, Baohua Jia, Hui Li, Jiaqi Ren, Yu Deng, Jiahao Chen, Ying Zhou, Kai Lei, Li Wang, Wei Liu, Hongwei Huang, Tianyi Ma
Abstract
Abstract Synthesizing H 2 O 2 from water and air via a photocatalytic approach is ideal for efficient production of this chemical at small‐scale. However, the poor activity and selectivity of the 2 e − water oxidation reaction (WOR) greatly restricts the efficiency of photocatalytic H 2 O 2 production. Herein we prepare a bipyridine‐based covalent organic framework photocatalyst (denoted as COF‐TfpBpy) for H 2 O 2 production from water and air. The solar‐to‐chemical conversion (SCC) efficiency at 298 K and 333 K is 0.57 % and 1.08 %, respectively, which are higher than the current reported highest value. The resulting H 2 O 2 solution is capable of degrading pollutants. A mechanistic study revealed that the excellent photocatalytic activity of COF‐TfpBpy is due to the protonation of bipyridine monomer, which promotes the rate‐determining reaction (2 e − WOR) and then enhances Yeager‐type oxygen adsorption to accelerate 2 e − one‐step oxygen reduction. This work demonstrates, for the first time, the COF‐catalyzed photosynthesis of H 2 O 2 from water and air; and paves the way for wastewater treatment using photocatalytic H 2 O 2 solution.