Generation of bimodal porosity via self-extra porogenes in nanoporous carbons for supercapacitor application

Abstract

In the present study, a facile strategy is proposed for generating bimodal porosity in porous carbons by using a sacrificed metal–organic framework (ZIF-8) as the precursor and additional silica colloids as extra porogenes via further self-assembly. Details in the formation of hierarchical structures are studied by time-dependent XRD and TEM characterizations. As-synthesized hierarchical porous carbons possess micropores (1.0 nm) and mesopores (3–20 nm) that are verified by TEM and N₂-sorption measurements. Specific information on carbon structures is supplied by XRD and Raman data. Electrochemical properties have been briefly investigated by cyclic voltammetry and impedance spectroscopy. A highest capacitance of 181 F g⁻¹ and lowest resistance of 0.21 Ω cm² are obtained between series of ZIF-8 derivative carbons, both of which, along with high electro-stability, show promising applications for these nanoporous carbons in supercapacitors.