Tungsten carbide@graphene nanoflakes: Preparation, characterization and electrochemical activity for capacitive deionization technology

In this present work, tungsten carbide (WC) nanoparticles were intercalated between graphene nanoflakes (GNFs) using sonication followed by hydrothermal treatment. Pristine WC, GNFs and a series of WC@GNFs nanomaterials were physically characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET) and water contact angle measurements. Cyclic voltammetry and electrochemical impedance studies were operated to investigate the electrochemical performance of these nanocomposites as efficient capacitive deionization (CDI) electrodes with improved electrochemical characteristics and specific capacitances in NaCl solution. Among the synthesized nanomaterials, WC@GNFs containing 10% WC displayed appreciable specific capacitance [580.00 F g(-1)], salt removal efficiency [95.50%], electrosorptive capacity [22.155 mg g(-1)] and charge efficiency [0.356] values. Accordingly, the measured results in this study indicate that WC@GNFs nanomaterials are suitable electrodes with an easy preparation route for efficient CDI technology. (C) 2020 Elsevier Inc. All rights reserved.