Tuning the Interlayer Interactions of 2D Covalent Organic Frameworks Enables an Ultrastable Platform for Anhydrous Proton Transport.

Abstract

The development of effective, stable anhydrous proton-conductive materials is vital but challenging. Covalent organic frameworks (COFs) are promising platforms for ion and molecule conduction owing to their pre-designable structures and tailor-made functionalities. However, their poor chemical stability is due to weak interlayer interactions and intrinsic reversibility of linkages. Herein, we present a strategy for enhancing the interlayer interactions of two-dimensional COFs via importing planar, rigid triazine units into the center of C3 -symmetric monomers. The developed triazine-core-based COF (denoted as TPT-COF) possesses a well-defined crystalline structure, ordered nanochannels, and prominent porosity. The proton conductivity was ≈10 times those of non-triazinyl COFs, even reaching up to 1.27×10-2 S cm-1 at 160 °C. Furthermore, the TPT-COF exhibited structural ultrastability, making it an effective proton transport platform with remarkable conductivity and long-term durability.