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

Abstract

A high electrochemical performance and cost effective solid state NiCo 2 O 4 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 NiCo 2 O 4 . 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 NiCo 2 O 4 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 NiCo 2 O 4 was evaluated by Brunauer -Emmett -Teller analysis (BET). The cyclic voltammetry (CV) reveals the faradaic reaction of the pure and co-doped NiCo 2 O 4 with excellent reversibility at higher scan rates. The maximum specific capacitance for pure and co-doped NiCo 2 O 4 nanoparticles (NPs) was achieved as 158.6 and 513.17 Fg À 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 codoped NiCo 2 O 4 was found to be 90.8 % and 95.07 % respectively for 3000 Cycles. The Zn, Mn co-doped NiCo 2 O 4 can be used as an excellent electrode for supercapacitor applications.

Iron‐Doped NiCo2O4 Nanoparticles: Synthesis via Homogeneous Precipitation Method and Studies on their Peroxidase‐like Activity

“…The bands observed at 556 cm −1 and 644 cm −1 are due to Co−O and Ni−O vibrations, respectively [34] . Significant shift of IR bands is not observed upon incorporation of iron in NiCo 2 O 4 nanoparticles and similar results have been reported by Pradeepa et al [41] …”

“…The bands observed at 556 cm À 1 and 644 cm À 1 are due to CoÀ O and NiÀ O vibrations, respectively. [34] Significant shift of IR bands is not observed upon incorporation of iron in NiCo 2 O 4 nanoparticles and similar results have been reported by Pradeepa et al [41] The FE-SEM images of pure and iron-doped NiCo 2 O 4 nanoparticles show formation of nanorods with spherical particles at the tip (Figure 3). Figure 4 shows the TEM images of pure NiCo 2 O 4 (NC-500) and iron-doped NiCo 2 O 4 nanoparticles (FeNC-0.1-500, FeNC-0.3-500, FeNC-0.5-500 and FeNC-0.7-500).…”

Enhanced Structural and Electrochemical Properties of Zn-Doped NiCo2O4 Synthesized by Low-Temperature Microwave Hydrothermal Process

“…A slight shifting of metal oxygen bands towards the higher wavelength (lower energy) side with the increase of Zn doping which indicates that the non-covalent interactions (Vanderwaals interactions) between Zn +2 ions, the Co 2+ and Co +3 ions, and the metal Oxygen bonds. 27 The surface morphology and elemental compositions of the samples under investigation were analyzed using a scanning electron microscope (SEM) are shown in Figs. 3a-3d.…”

Carbon-Encapsulated NCO4−β/C Hierarchical Nano-Microflowers for Electrocatalytic Dechlorination of Dichloromethane

“…Preparation of Bulk Phase NiCo 2 O 4 /C 1 without Special Structures. According to the method of Pradeepa and co-workers, 22 the bulk phase NiCo 2 O 4 without special structures was synthesized. After that, NiCo 2 O 4 /C 1 was similarly prepared by the above dopamine impregnation method as a comparative material of NCO 4−β /C 1 .…”