Design of flexible and green chemistry synthesis method for highly crystalline COFs for supercapacitor applications

Covalent organic frameworks (COFs) have attracted much attention in energy storage due to their porous network structure, large specific surface area, high crystallinity, and pseudocapacitive ability brought by redox reactions. However, the traditional synthesis method of COFs involves toxic solvents and requires high temperatures and pressure. Therefore, it is necessary to develop simple synthesis methods for large-scale practical application of COFs. This study investigated the synthesis and electrochemical properties of two kinds of COFs, which were synthesized through the reflux heating method and solvothermal method using tri(4-aminophenyl)amine (TAPA) and tris(benzaldehyde) (TFB) as monomers. The results indicate that COFs synthesized by the reflux heating method (Re-COF-TAFB) have better specific surface area, thermal stability, and electrochemical properties compared to those synthesized by the solvothermal method (So-COF-TAFB). Re-COF-TAFB has a specific capacitance of 248 F·g⁻¹ at 0.1 A·g⁻¹ and a capacitance retention rate of 104.13% after 10,000 charge and discharge cycles. This paper contributes to understanding COFs’ synthesis methods and their impact on material properties. Reflux heating is highlighted as an efficient technique for developing high-performance COF-based supercapacitors.