Boosting electrochemical efficiency of WO3@NiWO4 3 @NiWO 4 nanocomposite with carbon-based substrates to employ in high-performance supercapacitor application

Innovated WO3@NiWO4/carbon substrates (carbon nanotubes and reduced graphene oxide) nanocomposites were schemed through the multiple step synthesis. In order to fabricate the NiWO4, a hydrothermal method was selected. Also, WO3 nanodisk was synthesized on NiWO4 via an in-situ synthesis approach through the sonochemical route. Finally, during the mild hydrothermal condition, WO3@NiWO4 nanostructure was composited with carbon-based materials and used as supercapacitor electrode. The as-prepared nanocomposites display superb capacity and cyclability compared to pure nanostructures (i.e.WO3 and NiWO4) and binary nanocomposites namely WO3@NiWO4. The physicochemical characterization and compositional analysis of the assynthesized nanostructures were conducted with field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), Powder X-ray diffraction (XRD), Fourier transform infrared spectra (FT-IR) and Brunauer-Emmett-Teller analysis. Additionally, the electrochemical performance of as-designed products was investigated via cyclic voltammetry (CV), galvanostatic charge-discharge cycling (GCD) and electrochemical impedance spectroscopy (EIS). The optimum fabricated electrode (WO3@NiWO4/CNT-16 % (WNCNT-16 %)) provides an excellent specific capacitance of 1897.78 F g- 1 at a constant current density of 1 Ag- 1 compared to WO3@NiWO4/rGO (WNrGO-28 %) (580 Fg- 1), WO3@NiWO4 (535.55 F g-1), WO3 (200 F g- 1) and NiWO4 (202.22 F g-1) in the similar condition. WNCNT-16 % electrode shows excellent capacitance retention 96.63 % after 1000 cycles at a scan rate of 50 mV s-1, while WNrGO-28 % and WO3@NiWO4 electrodes have capacitance retention 89.61 % and 83.32 % in mentioned situation, respectively. According to this investigation as-schemed nanocomposite namely WNCNT-16 % could be a favorable candidate for using in highperformance electrochemical energy storage devices.