Imidazolate framework (Zn-Ni(MeIm)2) nanohybrids as electrodes for supercapacitor applications

Abstract

A typical solvothermal method was used to synthesize the imidazole framework (Zn-Ni(MeIm)2) and subsequently calcined under a nitrogen atmosphere (Zn-Ni(MeIm)2(N2-723K), and activated with KOH (Zn-Ni(MeIm)2(KOH). The samples were characterized by X-ray diffraction, field emission scanning electron microscopy, Fourier transform infrared spectroscopy, and an electrochemical analyzer system. The pseudocapacitive behavior was exhibited when Zn-Ni(MeIm)2 was used as a supercapacitor material in the electrolyte of 6 M KOH. The Zn-Ni(MeIm)2, (Zn-Ni(MeIm)2(N2-723K) and (Zn-Ni(MeIm)2(KOH) electrodes showed specific capacitances of 378, 192 and 573 Fg-1, respectively, at a current density of 5 A g-1. It still retained good performance and stability over 1000-cycles measurement. These results indicate that Zn-Ni(MeIm)2-derived compounds are promising materials for use as supercapacitors.