Covalent Organic Frameworks Containing Dual O ₂ Reduction Centers for Overall Photosynthetic Hydrogen Peroxide Production

Abstract

Covalent organic frameworks (COFs) are highly desirable for achieving high‐efficiency overall photosynthesis of hydrogen peroxide (H ₂O ₂) via molecular design. However, precise construction of COFs toward overall photosynthetic H ₂O ₂ remains a great challenge. Herein, we report the crystalline s‐heptazine‐based COFs (HEP‐TAPT‐COF and HEP‐TAPB‐COF) with separated redox centers for efficient H ₂O ₂ production from O ₂ and pure water. The spatially and orderly separated active sites in HEP‐COFs can efficiently promote charge separation and enhance photocatalytic H ₂O ₂ production. Compared with HEP‐TAPB‐COF, HEP‐TAPT‐COF exhibits higher H ₂O ₂ production efficiency for integrating dual O ₂ reduction active centers of s‐heptazine and triazine moieties. Accordingly, HEP‐TAPT‐COF bearing dual O ₂ reduction centers exhibits a remarkable solar‐to‐chemical energy efficiency of 0.65 % with a high apparent quantum efficiency of 15.35 % at 420 nm, surpassing previously reported COF‐based photocatalysts.