Investigation of electrochemical properties of microwave irradiated tungsten oxide (WO₃) nanorod structures for supercapacitor electrode in KOH electrolyte

Rod-like morphology of tungsten oxide (WO₃) nanostructures were successfully synthesized via simple microwave irradiation method for three different irradiation times. The Precipitation was obtained from a sodium tungstate salt solution and subsequent Microwave irradiation along with that furnace heating have been used to prepare the WO₃ nanostructures. Further investigation shows that monoclinic and orthorhombic crystal structures with a well-grown rod-shaped morphology of as-synthesized samples which were confirmed by XRD and HRTEM analysis. The optical absorption was measured by UV–vis spectroscopy and its band gap was calculated as the average value of 3.58 eV. The functional group linked with WO₃ was studied by Raman spectroscopy and confirmed the associated groups with WO₃. Finally, the suitability of as-prepared nanostructures for electrochemical supercapacitor was investigated by Cyclic Voltammetry (CV) and Galvanic Charge-Discharge (GCD) analysis, which revealed their highest specific capacitance 44 Fg⁻¹ at a current density of 0.5 Ag⁻¹. (paper)