Cyano‐Regulated Organic Polymers for Highly Efficient Photocatalytic H 2 O 2 Production in Various Actual Water Bodies

Abstract Photocatalytic production of H 2 O 2 has drawn significant attention in recent years, but the yield rate of current photocatalytic systems is still unsatisfactory. Moreover, the presence of various components in actual water bodies will consume the photogenerated charges and deactivate the catalyst, severely limiting the real applications of photocatalytic H 2 O 2 production. Herein, a cyano‐modified polymer photocatalyst is synthesized by Knoevenagel condensation with subsequent thermal polymerization. The introduction of cyano group and sulfer (S), oxygen (O) elements modulates the microstructure and energy band of the polymer catalyst, and the cyano group sites can effectively adsorb and activate O 2 , realizing the generation of H 2 O 2 in the two‐step single‐electron oxygen reduction process. The reported system achieves high H 2 O 2 generation rate up to 1119.2 µmol g −1 h −1 in various water bodies including tap water, river water, seawater, and secondary effluent. This simple and readily available catalyst demonstrates good anti‐interference performance and pH adaptability in photocatalytic H 2 O 2 production in actual water bodies, and its photodegradation and sterilization applications are also demonstrated. This study offers new insights in developing polymer catalysts for efficient photocatalytic production of H 2 O 2 in various water bodies for practical application.