Synthesis and characterization of ZIF-۶۷-NiO/graphene sponge forsupercapacitor applications

Nowadays, the use of electrical appliances to supply the daily electrical energy that canreplace the use of fossil fuels is very indispensable and important. Not only the harmfulphenomena of greenhouse gas production and the increase in earth's heat, but also thedependence of clean energy generation such as solar and wind energy on weather conditions, haspushed researchers towards the challenge of continuous energy supply [۱]. Therefore, amongelectrical devices capable of storing energy, in recent years, supercapacitors (SCs) with highenergy density and high charge/discharge speed have attracted the attention of researchers [۲]. Inthis study, to develop supercapacitors, a graphene sponge (GS) has been used as a threedimensionalsubstrate derived from graphene. Furthermore, to increase the energy density, theGS substrate has been decorated by using nanostructures such as zeolitic imidazolate framework-۶۷ (ZIF-۶۷) and nickel oxide (NiO). In this comparative study, the synthesized GS, ZIF-۶۷, NiO,ZIF-GS, NiO-GS, and ZIF-NiO-GS have been characterized by X-ray powder diffraction,Fourier transform infrared spectroscopy, and field emission scanning electron microscopycoupling with energy dispersive spectroscopy to investigate the structure, functional groups, andmorphology with elemental distribution, respectively. The obtained results of XRD show that thetarget ZIF-۶۷ has been correctly synthesized and has. Furthermore, the images related to thecarbon substrate e have shown the favorable sponge shape and it confirms the synthesis of GSsuccessfully. In addition, cyclic voltammetry, electrochemical impedance spectroscopy, andchronoamperometry studies have been used to measure the specific capacitance and the chargetransfer resistance of the desired structures

کلیدواژه ها:

NiO-ZIF-۶۷ ، Graphene sponge ، Supercapacitors ، EIS ، charge/discharge