Naphthalene‐Quinone Electron Donor–Acceptor Covalent Organic Polymers for Hydrogen Peroxide Photosynthesis in Pure Water

A 2,3‐diaminonaphthalene (DAN) 1,3,5‐triformylphloroglucinol (TP) β‐ketoenamine‐linked covalent organic polymer with naphthalene‐quinone electron donor (D)–acceptor (A) structure (DAN‐TP‐CKP) was synthesized using a one‐pot method. It exhibited a high H2O2 production rate of 1120 μmol gcat−1 h−1 in O2‐saturated water under visible light, together with better durability. The efficiency is attributed to its crystalline framework, large specific surface area (212 m2 g−1), strong visible‐light absorption, and efficient charge separation properties arising from its dense electron D–A structures. A two‐step single‐electron oxygen reduction reaction pathway with a probable four‐step mechanism further elucidates its H2O2 generation process. This work highlights D–A‐type naphthalene–quinone metal‐free polymer photocatalysts with efficient and durable H2O2 photosynthesis performance.