Custom‐Design of Strong Electron/Proton Extractor on COFs for Efficient Photocatalytic H<sub>2</sub>O<sub>2</sub> Production
Liyao Li, Ximeng Lv, Yuanyuan Xue, Huibo Shao, Gengfeng Zheng, Qing Han
Abstract
Abstract The development of photocatalysts with continuous electron extraction and rapid proton transfer could kinetically accelerate the artificial photosynthesis, but remains a challenge. Herein, we report the topology‐guided synthesis of a high‐crystalline triazine covalent organic framework (COF) decorated by uniformly distributed polar oxygen functional groups (sulfonic group or carboxyl) as the strong electron/proton extractor for efficient photocatalytic H 2 O 2 production. It was found that the polarity‐based proton transfer as well as electron enrichment in as‐obtained COFs played a crucial role in improving the H 2 O 2 photosynthesis efficiency (i.e., with an activity order of sulfonic acid‐ (SO 3 H‐COF)>carboxyl‐ (COOH‐COF)>hydrogen‐ (H‐COF) functionalized COFs). The strong polar sulfonic acid group in the high‐crystalline SO 3 H‐COF triggered a well‐oriented built‐in electric field and more hydrophilic surface, which serves as an efficient carrier extractor enabling a continuous transportation of the photogenerated electrons and interfacial proton to the active sites (i.e., C atoms linked to −SO 3 H group). As‐accelerated proton‐coupled electron transfer (PCET), together with the stabilized O 2 adsorption finally leads to the highest H 2 O 2 production rate of 4971 μmol g −1 h −1 under visible light irradiation. Meanwhile, a quantum yield of 15 % at 400 nm is obtained, superior to most reported COF‐based photocatalysts.