Synthesis of nitrogen-doped porous carbon from zeolitic imidazolate framework-67 and phenolic resin for high performance supercapacitors

Abstract

An one-pot method has been developed to synthesize a new type of composite material, which can be used as carbon source to produce electrode material for supercapacitors. Specifically, zeolitic imidazolate framework-67 (ZIF-67) crystal was synthesized firstly in 2-methylimidazol aqueous solution, then silica primary particles (from hydrolysis of tetraethylorthosilicate) and phenolic resin (from aggregation of resorcinol and formaldehyde) co-condensed on the surface of ZIF-67 crystal in the same system. The key to realize one-pot method is that 2-methylimidazol aqueous solution shows alkalescence, which can catalyze the hydrolysis of tetraethylorthosilicate and the aggregation of phenolic resin. After carbonization and remove of silica, the N-doped porous carbon (Carbon-ZSR) with high degree of graphitization, wide pore size distribution and maximum specific surface area was obtained. When it is used for supercapacitors as the electrode material, the Carbon-ZSR shows excellent electrochemical properties, large specific capacitance (305 Fg−1 at 1 Ag−1), high rate performance (229 Fg−1 keeps at 10 Ag−1) and excellent electrochemical stability (the specific capacitance maintains 98.4% after 5000 cycles at 10 Ag−1), which suggest that the ZIF-derived nitrogen-doped porous carbon is an outstanding electrode material for energy storage devices.