A symmetric ZnO-ZIF8//Mo-ZIF8 supercapacitor and comparing with electrochemical of Pt, Au, and Cu decorated ZIF-8 electrodes

MOF engineering with metal (oxides) has attracted much interest, mainly as electrode components in energy storage devices. Regarding the promising features of MOFs and contributing of nanoparticles in their electrochemical activities, we synthesized ZIF-8, and then the nanoparticles of ZnO, {Mo132}, Pt, Au, and Cu decorated into it to compare their supercapacitor results. Concerning the supercapacitor application, the nanostructures of ZnO, {Mo132}, Pt, Au, and Cu decorated-ZIF-8 (ZZIF8, MZIF8, PZIF8, AZIF8, CZIF8) as electrode materials were separately analyzed by galvanostatic cycling, and cyclic voltammetry (CV) tests during a three-electrode system. The maximum specific capacitance (SC) was obtained for ZZIF8 as 500 F g−1 and 763.7 F g−1 (1 mV s−1) at a current density of 0.5 A g−1 through the GCD and CV measurements, respectively. All electrodes showed good cycle stability within 5000 charge-discharge periods, while the retention capacity was achieved as 97.2% and 95.3%for ZZIF8 and MZIF8 (8 A g−1). It was followed by further arranging an asymmetric supercapacitor and investigated the capacitive behavior of the system. The two-electrode device worked in voltage 0.0–1.0 V with a SC of 269 F g−1 in 0.5 M aqueous Na2SO4 solution at 0.5 A g−1, where energy density calculated as high as 11.3 Wh kg−1 at a power density of 275 W kg−1. Also, the asymmetric supercapacitor exhibited excellent cycle stability with ~93% retention capacitance within 5000 periods (4 A g−1). This approach makes a reliable plan for the hybrid effect of engineered-MOFs with high surface area, beneficial of simultaneous charge storing mechanism of affordable and ease synthesis carbon frameworks and nanoparticles.