Structurally Tailored Covalent Triazine Frameworks as Multitasking Electrodes for Supercapacitors, HER, ORR, and Zinc–Air Batteries

Integrating multiple functionalities within a single material system is critical for the development of cost-effective, sustainable, and technologically advanced clean energy devices. We report a series of highly porous nitrogen-/oxygen-codoped covalent triazine frameworks ( Azo-Oxy-CTFs ), synthesized through dynamic cyclotrimerization of a low-cost azo-/hydroxy-functionalized benzonitrile monomer ( Azo-Oxy-CN ) in molten ZnCl 2 . The ionothermal synthetic conditions induce partial in situ structural rearrangement of initially formed organized triazine frameworks via carbonization and decomposition processes, generating amorphous architectures with well-defined porosity embedded with graphitic domains combining carbon defects and electroactive sites (pyridinic-N, graphitic-N, and carbonyl). The extent of rearrangement is strongly governed by the synthesis temperature, imparting distinct electrochemical properties across the series. Electrochemical assessment reveals trifunctionality: as supercapacitors, Azo-Oxy-CTFs deliver a specific capacitance of 216 F g –1, remarkable cyclic stability over 30000 cycles, and impressive specific energy (16.7 Wh kg –1 ) and power (3407 W kg –1 ); as electrocatalysts, they exhibit high performance for both oxygen reduction ( E 1/2 = 0.78 V) and hydrogen evolution reactions, with low overpotentials of 74.6 and 157.6 mV at 10 and 50 mA cm –2, respectively. When integrated as Zn–air battery cathodes, they deliver 144.8 mW cm –2 peak power density and stable operation for 100 h at 10 mA cm –2 with 3.5% voltage variation, surpassing commercial 20 wt % Pt/C.