Covalent Triazine Frameworks and Porous Carbons: Perspective from an Azulene‐Based Case
Kaiyue Jiang, Peipei Peng, Diana Tranca, Gangsheng Tong, Changchun Ke, Chenbao Lu, Jun Hu, Haiwei Liang, Jiantong Li, Shengqiang Zhou, Emmanuel Kymakis, Xiaodong Zhuang
Abstract
Abstract Covalent triazine frameworks (CTFs) are among the most valuable frameworks owing to many fantastic properties. However, molten salt‐involved preparation of CTFs at 400–600 °C causes debate on whether CTFs represent organic frameworks or carbon. Herein, new CTFs based on the 1,3‐dicyanoazulene monomer (CTF‐Azs) are synthesized using molten ZnCl 2 at 400–600 °C. Chemical structure analysis reveals that the CTF‐Az prepared at low temperature (400 °C) exhibits polymeric features, whereas those prepared at high temperatures (600 °C) exhibit typical carbon features. Even after being treated at even higher temperatures, the CTF‐Azs retain their rich porosity, but the polymeric features vanish. Although structural de‐conformation is a widely accepted outcome in polymer‐to‐carbon rearrangement processes, the study evaluates such processes in the context of CTF systems. A proof‐of‐concept study is performed, observing that the as‐synthesized CTF‐Azs exhibit promising performance as cathodes for Li‐ and K‐ion batteries. Moreover, the as‐prepared NPCs exhibit excellent catalytic oxygen reduction reaction (ORR) performance; hence, they can be used as air cathodes in Zn‐air batteries. This study not only provides new building blocks for novel CTFs with controllable polymer/carbon features but also offers insights into the formation and structure transformation history of CTFs during thermal treatment.