Microwave-assisted synthesis of Zn–WO3 and ZnWO4 for pseudocapacitor applications

• Novel nano-sized Zn-WO3 and ZnWO4 materials have been prepared.
• A new and simple solution growth technique was developed.
• Zn–WO3 and ZnWO4 could be used in pseudocapacitor applications.

Nanosized Zn–WO3 and ZnWO4 materials have been prepared by microwave irradiation method. The physico-chemical characterization of the prepared nanomaterials was carried out by X-ray diffraction (XRD) and high resolution-scanning electron microscopy (HR-SEM) techniques. The size and shape of the ZnWO4 material can be controlled by changing the temperature. The XRD analysis revealed the formation of monoclinic phase of the calcined nanopowder. The HR-SEM images showed the sphere and plate shape particles. The electrochemical behavior of the ZnWO4 modified electrodes was investigated using electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and galvanostatic charge–discharge (GCD) techniques. The synthesized material shows the pseudocapacitance. The specific capacitance of 35.70 F/g was achieved for the Zn–WO3 nanopowder.