Mechanochemistry-driven phase transformation of crystalline covalent triazine frameworks assisted by alkaline molten salts

Abstract

Covalent triazine frameworks (CTFs) have shown wide applications in the fields of separation, catalysis, energy storage, and beyond. However, it is a long-term challenging subject to fabricate high-quality CTF materials via facile procedures. Herein, a mechanochemistry-driven procedure was developed to achieve phase transformation of crystalline CTFs assisted by alkaline molten salts. The transformation of CTF-1 from staggered AB to eclipsed AA stacking mode was achieved by short time (30 min) mechanochemical treatment in the presence of molten salts composed of LiOH/KOH, generating high-quality CTF-1 material with high crystallinity, high surface area (625 m² g⁻¹), and permanent/ordered porosity without carbonization under ambient conditions. This facile procedure could be extended to provide nanoporous three-dimensional CTF materials.