MOF(ZM)/Potassium Citrate-Derived Composite Porous Carbon and Its Electrochemical Properties

Abstract

Metal-organic frameworks are compounds with a reticulated skeletal structure formed by chemically bonding inorganic and organic units that are widely used in many fields, such as photocatalysis, gas separation and energy storage, because of their unique structures. In this paper, we prepared a metal-organic framework [(μ 2 -2-methylimidazolyl) 12 -Zn(ii) 6 -H 18 O 10 ] n (ZM) with well-developed pores and high specific surface area of MOFs by the solution method. And MOF-derived porous carbon was prepared by the direct charring method in an argon atmosphere using a mixture of ZM, ZM and potassium citrate as carbon precursors. Characterization analysis revealed that the maximum specific surface area of ZMPC-800-1:15 was 2014.97 m 2 •g −1 , and the pore size structure was mainly mesoporous. At a current density of 1.0 A•g −1 the specific capacitance of ZMC-800 and ZMPC-800-1:15 was 121.3 F•g −1 and 226.6 F•g −1 , respectively, with a substantial increase of 86.8%. The specific capacitance of ZMPC-800-1:15 decays to 168.8 F•g −1 , with a decay rate of 25.5%, when the current density increases to 10.0 A•g −1 . After 5000 constant current charge/ discharge cycles, the capacitance retention rate was still 96.41%. These results prove that the application of MOF-derived carbon materials in future supercapacitors is very promising.