Designed Synthesis of a 2D Porphyrin‐Based sp 2 Carbon‐Conjugated Covalent Organic Framework for Heterogeneous Photocatalysis

The construction of stable covalent organic frameworks (COFs) for various applications is highly desirable. Herein, we report the synthesis of a novel two‐dimensional (2D) porphyrin‐based sp 2 carbon‐conjugated COF (Por‐sp 2 c‐COF), which adopts an eclipsed AA stacking structure with a Brunauer—Emmett—Teller surface area of 689 m 2  g −1 . Owing to the C=C linkages, Por‐sp 2 c‐COF shows a high chemical stability under various conditions, even under harsh conditions such as 9  m HCl and 9  m NaOH solutions. Interestingly, Por‐sp 2 c‐COF can be used as a metal‐free heterogeneous photocatalyst for the visible‐light‐induced aerobic oxidation of amines to imines. More importantly, in comparison to imine‐linked Por‐COF, the inherent structure of Por‐sp 2 c‐COF equips it with several advantages as a photocatalyst, including reusability and high photocatalytic performance. This clearly demonstrates that sp 2 carbon‐linked 2D COFs can provide an interesting platform for heterogeneous photocatalysis.