Assessing High-Performance Energy Storage of the Synthesized ZIF-۸ and ZIF-۶۷

Zeolitic imidazolate frameworks (ZIF-۸ and ZIF-۶۷) were synthesized for energy storage by utilizing cobalt (II) nitrate hexahydrate, zinc nitrate hexahydrate, and ۲-methyl imidazole. The redox peaks in the CV plots showed the existence of faradaic processes. The specific capacitance of ZIF-۸ and ZIF-۶۷ reduces with an increase in scan rate. ZIF-۸ and ZIF-۶۷ have estimated specific capacitances of ۶۲۵, ۳۱۲, ۲۰۸, ۱۵۶, and ۱۲۵ F/g and ۹۳۲, ۴۶۸, ۳۱۲, ۲۳۴, and ۱۸۷ F/g at scan rates of ۱۰ to ۵۰ mV/s. ZIF-۸ and ZIF-۶۷ have electrolyte resistances of ۱.۲۵ and ۱.۱۵ Ω, respectively, with active electrode resistances of ۰.۰۳ and ۰.۰۲ Ω. Great capacitive performance was indicated by the low charge transfer resistance seen in the Nyquist plots. Both ZIF-۸ and ZIF-۶۷ have estimated specific capacitances of ۲۷۶.۹۱ F/g according to the GCD tests. ZIF-۸ and ZIF-۶۷ had an energy density of ۷۹۹۹.۸۹ when the current density was ۲.۰ A/g. ZIF-۸ and ZIF-۶۷ nanocrystals differ in their XRD patterns, as the structure of ZIF-۸ remains intact. The nanoparticles exhibit high crystallinity, as evidenced by the distinct peaks observed, particularly the sharp (۰۰۱) peak at ۷.۴o. The high-pitched and defined peak at the ۲θ position of ۷.۶° confirmed the crystalline nature of synthesized ZIF-۶۷. The (۰۱۱) crystal plane was identified as the source of the intense peak at ۲θ position ۷.۶°. The bandgap value of ZIF-۶۷ is ۳.۲۷ eV, in contrast to ZIF-۸ which has a value of ۳.۰ eV.