Fabrication of nitrogen and ZnO doped on carbon particles obtained from waste biomass and their use as supercapacitor electrodes for energy storage

In this study, activated carbon (PPAC) is produced from pomegranate peel waste by activation of sodium hydroxide (NaOH) in the first stage. In the second stage, ammonia activation for nitrogen doping is carried out on PPAC (N-doped PPAC). In the third stage, zinc oxide (ZnO) doping is carried out on the obtained N-doped PPAC sample (ZnO@N-doped PPAC). The surface properties of the produced composite are examined by scanning electrode microscope (SEM), X-ray diffraction analysis (XRD), Energy dispersive X-ray (EDX), Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy(XPS), micro Raman and nitrogen adsorption analyses. The electrochemical performance of the supercapacitor is investigated by cyclic voltammetry (CV), charge-discharge curves(GCD), and electrochemical impedance spectroscopy (EIS). N-doped PPAC and ZnO@Ndoped PPAC composite materials are used as supercapacitor electrodes. Specific capacitance values of 207.4 and 265.2 F/g in 1 M sulfuric acid(H2SO4) are obtained with N-doped PPAC and ZnO@N-doped PPAC electrodes, respectively. Additionally, cycle stability is achieved with a capacitance retention of approximately 86% after 5000 cycles at 0.6 A/g. The maximum energy density and power density of ZnO@N doped PPAC were calculated as 7.29 Wh/kg and 3600 Wh/kg, respectively.