Transformation Strategy for Highly Crystalline Covalent Triazine Frameworks: From Staggered AB to Eclipsed AA Stacking
Zhenzhen Yang, Hao Chen, Song Wang, Wei Guo, Tao Wang, Xian Suo, De‐en Jiang, Xiang Zhu, Ilja Popovs, Sheng Dai
Abstract
Fabrication of crystalline covalent triazine frameworks (CTFs) under mild conditions without introduction of carbonization is a long-term challenging subject. Herein, a tandem transformation strategy was demonstrated for the preparation of highly crystalline CTFs with high surface areas under mild and metal- and solvent-free conditions. CTF-1 with a staggered AB stacking order (orange powder) obtained in the presence of a catalytic amount of superacid at 250 °C was transformed to highly crystalline CTF-1 with an eclipsed AA stacking order (greenish powder) and surface area of 646 m2 g–1 through annealing at 350 °C under nitrogen. The strategy can be extended to the production of crystalline fluorinated CTFs with controllable fluorine content. This finding unlocks opportunities to design crystalline CTFs with tunable photoelectric properties.