Supercapacitive property of metal–organic-frameworks with different pore dimensions and morphology

Three dicarboxylic acids with different molecular lengths were used as organic linkers to manipulate pore size and surface area of the cobalt based metal–organic-frameworks (MOFs). The pore size and BET surface area of the MOFs were determined and the influence of pore size and surface area on the supercapacitive performance of the MOFs was studied using cyclic voltammetry and chronopotentiometry. Among three MOFs investigated in the present study, the MOF with longer organic linker had larger pores, larger surface area and the MOF film at the electrode surface had a continuously interconnected leaflet like microstructure with less number of structural interfaces which provide the free path for charge transfer. This MOF electrode exhibited highest supercapacitive properties with 179.2 F g−1, 31.4 Wh kg−1, and 5.64 kW kg−1 of specific capacitance, energy density and power density, respectively.

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► Manipulation of pore size and surface area of Co-based MOF using different length of organic linkers.
► Fabrication of thin film of MOFs on an ITO–glass substrate.
► Investigation of supercapacitive and other electrochemical properties of the MOF films.
► MOF with larger pores and larger surface area exhibited higher supercapacitive performance.