Nanoscale Zn-MOF enwrapped polymer nanocomposite as electrode material for enhanced energy storage system

Polymer nanocomposites (PNCs) can be used as a supercapacitor electrode material in a variety of ways due to the different doping patterns of polymers and different metal oxides. Due to their outstanding shape, excellent functional connectivity, metallic substrates, and high specific surface area, metal-organic frameworks (MOFs) are model materials for the construction of electrodes in electrochemical energy storage devices. The combination of polymers and MOF as electrode materials exhibits extra advantages that are necessary for further investigation. In this study, poly(vinyl alcohol)(PVA)/poly(vinyl pyrolidone)(PVP) blended hybrid nanocomposites embedded with zeolitic imidazolate framework-8 (ZIF-8) have been prepared by solution casting. X-ray diffractometer (XRD), Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) were used to analyse structural studies and surface morphology observations. Notably, the Zn-N band's stretching vibration occurred at 418 cm−1, indicating that zinc ions and the nitrogen atoms in the 2-methylimidazole ligand combined chemically to produce imidazolate. All the results confirm the successful preparation of ZIF-8 anchored polymer nanocomposites. From electrical modulus analysis, a single relaxation peak was observed in all PNCs. Electrochemical capacitance has been studied by electrochemical techniques. Specific capacitance, cyclic charge, and discharge tests of polymer nanocomposites have been measured. Coulombic efficiencies were 99.36, 98.95, and 99.63% for PVA/ZIF-8, PVP/ZIF-8, and PVA/PVP/ZIF-8, respectively. It possesses high specific energy densities of 3.44, 3.61, and 4.44 mWh cm−2 at specific power densities of 732, 999, and 885 mW cm−2 for ASC (PVA/ZIF-8)//AC, (PVP/ZIF-8) //AC, and (PVA/PVP/ZIF-8)//AC, respectively. The fabricated biocompatible PNCs exhibit great potential to provide an alternative to conventional supercapacitors (SCs).