Construction of Triphenylamine‐based Two‐dimensional Covalent Organic Frameworks for High‐performance Capacitive Energy Storage and Exploration of Redox Units

Abstract

Covalent organic frameworks (COFs) have received more interest as energy storage devices for their unique topological structure and excellent electrochemical performance. However, the confirmation of active center and the mechanism of charge storage in COFs supercapacitors is still a significant challenge. Here, a series of Tp‐based COFs with different link units have been obtained through Schiff base reaction. All the synthesized COFs exhibited high crystallinity and excellent thermal stability. Based on similar structure, electrochemical analysis and DFT calculation was used to identify the redox active sites. Because of their conjugated structures containing redox‐active triphenylamine groups, the obtained a‐COFs exhibited specific capacitance of 115 F ⋅ g−1 in 1 M H2SO4 at 0.1 A ⋅ g−1 and retained 70 % capacitive after 1000 cycles. Our findings provide a new routine for designing new COFs electrode materials.