Rational synthesis of graphitic porous carbon with high content nitrogen doping via ultra-fast pyrolysis of ZIF-8 for electrochemical capacitor with enhanced performance

Abstract

In this work, we proposed an effective strategy to prepare nitrogen-doped popcorn-like porous carbons (NPPCs) via ultra-fast carbonization of zeolitic immidazolate frameworks (ZIFs-8), where the ZIFs-8 acted as carbon precursor as well as the template. The obtained NPPCs possess popcorn-like morphology with large specific surface area of 1243[Formula: see text]m2/g, total pore volume of 1.48[Formula: see text]cm3/g and high nitrogen content. Remarkably, the average pore diameter of NPPCs was 4.72[Formula: see text]nm, indicating the presence of amount substantial mesopores. As the electrode of supercapacitor, the NPPCs revealed a relatively high specific capacitance of 610.4[Formula: see text]F/g in KOH (6[Formula: see text]mol/L) at 5[Formula: see text]mV/s. Even the scan rate was increased to 50[Formula: see text]mV/s, an impressive capacity of 424.8[Formula: see text]F/g can be achieved, suggesting good rate capability. Besides, it exhibited outstanding cycling stability with 93% of specific capacitance retention after 10,000 GCD cycles. Moreover, the NPPCs electrode demonstrated high electrochemical performance and stability by designing the coin-type and flexible supercapacitor. The large specific surface area, abundant accessible mesoporosity and novel nanostructure are account for the superior performance.