Ni۲+-doped ZIF-۶۷ MOF with Excellent Supercapacitive Performance

In the recent years, metal-organic frameworks (MOFs) have emerged as an engrossing category of functional materials with some unique properties such as high porosity and high specific surface area for energy storage applications. Herein, a cathodic electrodeposition strategy was utilized to prepare a Ni۲+-doped ZIF-۶۷ MOF with completely porous morphology. Structural characterization revealed that Ni۲+ and Co۲+ metal ions are uniformly distributed on the deposited films onto the nickel foam. The fabricated ready-to-use Ni-ZIF-۶۷/NF electrode was characterized with various techniques of X-ray diffraction (XRD), Fourier-transform infrared (FT-IR), Field-emission scanning electron microscope (FE-SEM), Energy dispersive X-ray analysis (EDAX), and Energy dispersive spectroscopy (EDS) mapping. Energy storage behaviour of the prepared Ni-ZIF-۶۷/NF electrode was also measured using cyclic voltammetry (CV), galvanostatic charge/discharge, and electrochemical impedance spectroscopy (EIS) tests in ۲M KOH. The Ni-ZIF-۶۷/NF electrode exhibited excellent specific capacitance of ۱۱۲۵ F g–۱ at a discharging load of ۱ A g–۱, where it still preserved ۶۹.۵% of initial capacitance at an applied high-rate load of ۲۰ A g–۱. Additionally, the Ni-ZIF-۶۷/NF electrode showed ۸۸.۴% of its capacitance at the end of ۶۰۰۰th cycle.

کلیدواژه ها:

Metal-organic frameworks ، Free-standing electrode materials ، ZIF-۶۷ ، Porous structure ، Supercapacitors