Inwardly Directed Linker Propagation: Constructing 3D Covalent Organic Frameworks for Efficient H ₂ O ₂ Photosynthesis

Abstract The limited design strategy of three‐dimensional covalent organic frameworks (3D COFs) greatly restricts their structural diversification and potential applications. Herein, we propose an inwardly directed linker propagation strategy for the targeted assembly of 3D COFs (COF‐IN‐1 and COF‐IN‐2) and compare them with outwardly directed expanded COFs (COF‐OUT‐1 and COF‐OUT‐2). COF‐OUTs exhibit planar heteroporous 2D frameworks with cpt topology, while COF‐INs engineer controlled triple entanglements into networks, forming 3D frameworks with acs topology. Moreover, the COFs assembled via inwardly directed linker propagation effectively enhanced the production of H 2 O 2 photosynthesis. To demonstrate the application potential, a biphasic fluid system was constructed for continuous H 2 O 2 photosynthesis and extraction. This work not only expands the design strategy for achieving 3D COFs but also demonstrates that the dimensional regulation of frameworks and tuning of applications can arise from different expanding directions of the linkers.