Controlled Microwave-Assisted Synthesis of Covalent Organic Frameworks Opens the Way Toward More Suitable Porous Supercapacitor Electrodes
Hugo Lavillunière, Thuan‐Nguyen Pham‐Truong, Thi Khanh Ly Nguyen, Cédric Vancaeyzeele, Pierre‐Henri Aubert
Abstract
Seeking efficient materials is still the key process for achieving high-performance electrical double-layer capacitor-type supercapacitors. In the present work, the synthesis of a well-known covalent organic framework, COF-5, was revisited and optimized by a microwave irradiation-assisted solvothermal approach. The highest Brunauer–Emmett–Teller specific surface area ever of 2600 m 2 g –1 was achieved for this material along with a reaction yield of >90% with a reduced reaction time. This study provides further evidence on the real convenience of using microwave irradiation as an alternative route for efficiently synthesizing covalent organic framework-based materials. Indeed, the electrical conductivity increases by 4 orders of magnitude up to 2.35 × 10 –2 S cm –1 . Furthermore, the synthesized COF-5 was evaluated as-prepared or together with conducting additives as active electrode materials for supercapacitor applications. Accordingly, a specific capacitance of 100 F g –1 at 2 mV s –1 was obtained after the activation process. Importantly, the better organization of the structure of the COF strongly enhances its stability over a potential range of 1.3 V at 100 mV s –1 for 100 000 cycles in aqueous electrolytes.