Convenient Aqueous‐Phase Synthesis of Covalent Organic Frameworks for Anhydrous Proton Conduction

Covalent organic frameworks (COFs) as a kind of emerging materials has been widely concerned. Developing and recovering new COF materials is of great importance for anhydrous proton conduction, most of the synthesis methods are not organic solvent phase or convenient enough, which would inevitably lead to solvent waste and increase environmental burden. Herein, a method of COF synthesis in aqueous phase is developed, which is used for nonpolluting and sustainable fabrication. Benefits from the suitable channels and stability of HCOF‐1, the composite material H 3 PO 4 @HCOF‐1 exhibit high proton conductivity (1.29 × 10 −4 S cm −1 ) at 413 K and the crystallinity of HCOF‐1 is maintained well after measurements. This work broadens the scope of COF synthesis and promotes the development of anhydrous proton conduction.