Improving the properties of nickel organic framework as electrode materials for supercapactiors by introducing functional groups

Abstract

To improve the redox activity of metal organic framework (MOF), functional groups have been introduced into organic framework to prepare Ni-MOF-NO2 and Ni-MOF-NH2 with solvothermal method. Physical and electrochemical characterization using SEM, EDS, XRD and BET shows that Ni-MOF-NH2 possesses thinner sheet-like structure, higher specific surface area and excellent electron transfer ability, which have activated the metal center Ni. A specific capacitance as high as 1024.4 F g-1 has been achieved for Ni-MOF-NH2 in the potential window of 0-0.45 V at 100 mV S-1, much higher than that of Ni-MOF-NO2 (353.9 F g-1) and Ni-MOF (399.5 F g-1). The introduction of electron-donating group-NH2 not only influences the morphology and specific surface area of MOF material, but also increases the electron cloud density of the metal active center, activates metal center Ni and alleviates the polarization of electrode.