Rufan Chen, Ji-Long Shi, Yuan Ma, Guiqing Lin, Xianjun Lang, and Cheng Wang*
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 sp2 carbon-conjugated COF (Por-sp2c-COF), which adopts an eclipsed AA stacking structure with a Brunauer—Emmett—Teller surface area of 689 m2 g-1. Owing to the C=C linkages, Por-sp2c-COF shows a high chemical stability under various conditions, even under harsh conditions such as 9M HCl and 9M NaOH solutions. Interestingly, Por-sp2c-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-sp2c-COF equips it with several advantages as a photocatalyst, including reusability and high photocatalytic performance. This clearly demonstrates that sp2 carbon-linked 2D COFs can provide an interesting platform for heterogeneous photocatalysis.