Dual electrochemical application of r-GO wrapped ZnWO₄/Sb nanocomposite

ZnWO 4 /Sb nanorods and r-GO-ZnWO 4 /Sb nanocomposite have been prepared using a single step solvothermal method. The prepared nanocomposites have been characterized using x-ray diffractometer (XRD), Scanning Electron Microscope (SEM), High Resolution Transmission Electron Microscope (HR-TEM), Raman and Brunauer–Emmett–Teller (BET). The x-ray photoelectron spectroscopy (XPS) technique was used to determine the elemental composition of ZWS-5 (5 mg r-GO-ZnWO 4 /Sb) composite. The XRD reveals the monoclinic wolframite structure of ZnWO 4 /Sb and r-GO-ZnWO 4 /Sb. SEM and HRTEM confirms that the ZnWO 4 /Sb has been decorated on the r-GO sheets. The electrochemical performance of the prepared samples towards the Hydrogen Evolution Reaction (HER) and dopamine sensing has been tested using electrochemical techniques. Onset potential of 265 mV @10 mA cm −2 , lower Tafel slope (95 mV dec −1 ), high electrochemical surface area (1383.216 m 2 g −1 ) and high specific site density (18.551 06 × 10 21 g −1 ) of ZWS-5 reveals the high electrocatalytic activity of the composite towards HER. Chronoamperometric dopamine sensing shows that ZWS-5 has the superior sensing performance with highest specific sensitivity (723 μ A μ M −1 μ g −1 ), lowest limit of detection (0.9624 μ M), along with a good selectivity. Results suggest that the r-GO-ZnWO 4 /Sb nanocomposite is a good candidate for the HER and electrochemical dopamine sensor. The incorporation of r-GO nanosheets with ZnWO 4 /Sb (ZWS) nanorods enhances the specific and electrochemical surface area, which accounts for the high electrocatalytic activity of the composite.