Sulfone‐Modified Covalent Organic Frameworks Enabling Efficient Photocatalytic Hydrogen Peroxide Generation via One‐Step Two‐Electron O2 Reduction

Abstract Photocatalytic oxygen reduction reaction (ORR) offers a promising hydrogen peroxide (H 2 O 2 ) synthetic strategy, especially the one‐step two‐electron (2e − ) ORR route holds great potential in achieving highly efficient and selectivity. However, efficient one‐step 2e − ORR is rarely harvested and the underlying mechanism for regulating the ORR pathways remains greatly obscure. Here, by loading sulfone units into covalent organic frameworks (FS‐COFs), we present an efficient photocatalyst for H 2 O 2 generation via one‐step 2e − ORR from pure water and air. Under visible light irradiation, FS‐COFs exert a superb H 2 O 2 yield of 3904.2 μmol h −1 g −1 , outperforming most reported metal‐free catalysts under similar conditions. Experimental and theoretical investigation reveals that the sulfone units accelerate the separation of photoinduced electron‐hole (e − ‐h + ) pairs, enhance the protonation of COFs, and promote O 2 adsorption in the Yeager‐type, which jointly alters the reaction process from two‐step 2e − ORR to the one‐step one, thereby achieving efficient H 2 O 2 generation with high selectivity.