A Facile One-Pot Hydrothermal Synthesis of Zn, Mn Co- Doped NiCo2O4 as an Efficient Electrode for Supercapacitor Applications

摘要

A high electrochemical performance and cost effective solid state NiCo2O4 material was synthesized by hydrothermal method. The performance of the supercapacitor material was investigated by incorporating the zinc and manganese in the crystal structure of NiCo2O4. The structure and morphology were confirmed by X-ray diffraction (XRD) pattern and Field Emission Scanning Electron Microscope (FE-SEM), and High Resolution Transmission Electron Microscope (HR-TEM). The optical absorption spectra of the pure and co-doped NiCo2O4 were investigated by UV-Vis analysis and the bandgap energy was found to be 4.38 and 2.98 eV respectively. Photoluminescence spectra (PL) reveal the blue and green emission peaks were found at 364, 376 and 488 nm respectively. The pore size and surface area of Mn, Zn co-doped NiCo2O4 was evaluated by Brunauer -Emmett –Teller analysis (BET). The cyclic voltammetry (CV) reveals the faradaic reaction of the pure and co-doped NiCo2O4 with excellent reversibility at higher scan rates. The maximum specific capacitance for pure and co-doped NiCo2O4 nanoparticles (NPs) was achieved as 158.6 and 513.17 Fg~(-1) respectively. Further, the electrochemical impedance spectroscopy (EIS) and galvanostatic charge discharge (GCD) were performed to identify the resistance and rate capability of the electrode materials. The cyclic stability of pure and Zn, Mn co-doped NiCo2O4 was found to be 90.8% and 95.07% respectively for 3000 Cycles. The Zn, Mn co-doped NiCo2O4 can be used as an excellent electrode for supercapacitor applications.