From ZIF nanoparticles to hierarchically porous carbon: toward very high surface area and high-performance supercapacitor electrode materials
Porous carbon materials with a high surface area have attracted considerable attention for their potential application in electrochemical energy storage. In this study, a high-performance capacitive energy storage material based on hierarchically porous carbon was successfully prepared from a new nanoscale ZIF (zeolitic imidazolate framework) precursor, JUC160. The effects of the activating reagent KOH on the textural characteristics and supercapacitor performances of ZIF-derived porous carbons have been carefully evaluated. The JUC160-700 sample has a high surface area (SBET = 3253 m2 g−1), a hierarchical porous structure with micro-/mesopore frameworks and an appropriate degree of graphitisation, all of which are crucial for the enhancement of electrochemical performance. In electrochemical evaluation, JUC160-700 exhibits an ultra-high capacitance (386 F g−1 at 1 A g−1), good rate capability (71.8% retention at 20 A g−1) and long-term cycling stability (>99.9% over 10 000 cycles). This remarkable performance indicates that ZIF-derived porous carbon could be an ideal electrode material for advanced supercapacitors and other electrochemical energy storage devices.