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 (H₂ O₂ ) 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 H₂ O₂ generation via one-step 2e^- ORR from pure water and air. Under visible light irradiation, FS-COFs exert a superb H₂ O₂ 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 O₂ adsorption in the Yeager-type, which jointly alters the reaction process from two-step 2e^- ORR to the one-step one, thereby achieving efficient H₂ O₂ generation with high selectivity.