The electrochemical performance of SnO2 quantum dots@zeolitic imidazolate frameworks-8 (ZIF-8) composite material for supercapacitors

SnO2 quantum dots@ZIF-8 is successfully synthesized via a simple in-situ epoxide precipitation route and investigated as an electrochemical pseudo-capacitor material in 6 M KOH electrolyte. Structural characterizations illustrate the dispersion of SnO2 quantum dots in the ZIF-8. The porous structure combined with SnO2 quantum dots maximizes the utilization of active material, resulting in a high specific capacitance. A maximum specific capacitance of the SnO2 quantum dots@ZIF-8 can reach up to 931 F g−1 at a scan rate of 5 mV s−1, which is far higher than SnO2 quantum dots (241 F g−1) and ZIF-8 (99 F g−1). Meanwhile, SnO2 quantum dots@ZIF-8 exhibits a good cycling stability over 500 cycles.