Synthesis and characterization of nanostructured Ni-WO3 and NiWO4 for supercapacitor applications

Ni-WO3 and NiWO4 nanopowders have been prepared by microwave irradiation method. The prepared nanopowders were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Scanning electron microscopy (SEM), Energy dispersive X-ray spectroscopy (EDX), Vibrating sample magnetometer (VSM) techniques. The XRD pattern revealed the formation of orthorhombic and monoclinic phase for the as-synthesized and heat treated samples, respectively. The Ni-WO3 and NiWO4 samples show the nanoporous morphologies and it was confirmed by SEM. The VSM observation showed ferromagnetic properties of both as-prepared and heat-treated nanopowders. The electrochemical performance of the Ni-WO3 and Ni-WO4 coated electrodes has been investigated using electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and Galvanostatic charge-discharge (GCD) techniques. The maximum specific capacitance of 171.28 F/g was achieved for the Ni-WO3 nanopowder. (C) 2015 Elsevier B.V. All rights reserved.