Microwave-assisted synthesis of cobalt doped WO3 nanostructure as an electrode material for supercapacitor

The present work demonstrates the improvement in the pseudocapacitive performance of Cobalt (1, 3, and 5 wt%) doped Tungsten oxide (WO3) nanoparticles synthesized by the microwave irradiation method. X-ray diffraction and Raman spectra analysis indicate the successful doping of Co in the WO3 crystal matrix. Meanwhile, Co doping influences the surface morphology of pure WO3 by forming more smaller particles with elongation in the long axis. The specific surface area of WO3 (125.32m² g⁻¹) is increased by two times after doping of Co in WO3 (232.1 m² g⁻¹). Moreover, the electrochemical performance of 5 wt% Co doped WO3 is improved by five times higher than pristine WO3, ascribed to its high surface area and porosity. Also, it achieves the highest specific capacitance (517 F g⁻¹) and energy density (14.55 Wh kg⁻¹) at 1 A g⁻¹ current density. The synergetic effect of the change in surface area and increased porosity due to doping of Co shows the enhancement in the electrochemical performance of WO3.