Covalent Organic Framework Derived Carbons as Supercapacitors

Abstract

Covalent organic frameworks (COFs) are a new class of porous materials which are basically crystalline organic porous polymers. In the last decade, COFs have been studied intensively for its diverse chemical nature and applications2. COFs have been prepared to employ different chemistries like boronic ester formation, Schiff base formation, hydrazine bond formation, benzimidazole bond formation etc. Among them, Schiff base COFs are well explored because of its diverse number of building block library available3. COFs have found potential applications in gas storage4, separation5, heterogeneous catalysis6, energy storage7 etc. Still, COFs suffer stability and conductivity issues in different applications8. Recently, very few COFs are burnt to generate porous carbons9. Porous carbons from COFs would have few advantages over carbon generated from other precursors. First of all, COFs due to its ordered structure would generate ordered crystalline heteroatom doped carbon10, which will have more effect on the structure-property relationship. Secondly, the conductivity of the material can be increased by controlled carbonization. COFs are a very bad conductor of electricity. But on carbonization, the conductivity issue can be resolved and the final carbon can bring improved performance for different electrochemical applications11. Still, there are disadvantages of COF-derived carbons in terms of specific applications like carbon capture. The carbon doesn’t have good selectivity of CO2 over N2. Despite the advantages and disadvantages COF-derived carbon are now widely used for different applications like energy storage, electrochemical water oxidation and reduction etc.