Synthesis and characterization of WC@GNFs as an efficient supercapacitor electrode material in acidic medium

Abstract

A two-step route to the preparation of graphene (G) nanoflakes (NFs), designed with tungsten carbide (WC) nanoparticles (WC@GNFs), through microwave irradiation and hydrothermal treatments. A uniform distribution of the WC nanoparticles on the graphene layers was confirmed through scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses. Additionally, X-ray diffraction (XRD) study demonstrated the presence of the characteristic crystal planes of tungsten carbide on those of graphene. An increase in the graphitization degree (G/1D = 4.9) of the WC@GNF nanocomposite was determined by Raman spectroscopy. These highlighted physical properties enabled the application of this nanomaterial, as a supercapacitor electrode in an H2SO4 electrolyte. The cyclic voltammetry (CV) scans indicated that the charging process was controlled by a pseudocapacitive contribution in conjunction with the electrical double-layered features. A specific capacitance, 1009.52 F/g, was estimated, at 1 mV/s, with improved retention of 106% during repeated cycles, at 20 A/g for 2000 cycles to outperform the obtained results for most relevant W-based nanomaterials. Therefore, the method of fabricating WC, proposed in this work, could be a simple method of examining the performance of a series of comparable transition metal carbides toward the technology of supercapacitors technology.