Wool roving textured reduced graphene oxide-HoVO4-ZnO nanocomposite for photocatalytic and supercapacitor performance

Reduced graphene oxide-HoVO4-ZnO nanocomposite was prepared via simple hydrothermal method and characterized by X-ray powder diffraction (XRD), Field Emission Scanning Electron Microscopy (FE-SEM), Energy-Dispersive Spectroscopy (EDX), High-Resolution Transmission Electron Microscopy (HR-TEM), X-Ray Photoelectron Spectroscopy (XPS), FT-Raman, UV-Visible Diffuse Reflectance Spectroscopy (DRS), Electrochemical impedance spectroscopy and Cyclic Voltammogram(CV). The XRD pattern confirmed the formation of hexagonal wurtzite structure of ZnO and monoclinic scheelite structure of HoVO4. FE-SEM images depicted the Wool roving textured reduced Graphene Oxide-HoVO4-ZnO catalyst. As prepared rGO-HoVO4-ZnO exhibits highest photodegradation efficiency achieving at 97.2% and 98% for ibuprofen (IBF) and ciprofloxacin (CIP) respectively in 60 min under UV light illumination. Superoxide radicals (O-2(center dot-)) play an important role in the decomposition of IBF and CIP. Prepared catalysts were found to be stable and reusable even after six consecutive cycles without loss of catalyst. Also Besides, the electrochemical efficiency and galvanostatic charge-discharge of the rGO-HoVO4-ZnO and HoVO4-ZnO composites electrode materials were evaluated by cyclic voltammetry. rGO-HoVO4-ZnO composite showed higher specific capacitance of 322 Fg(-1), compared to HoVO4-ZnO (252 Fg(-1)) in neutral aqueous electrolyte. The enhancement of specific capacitance of the composite electrode is mainly due to the interconnected conductive network as well as synergism of rGO. The experimental results reveal that rGO-HoVO4-ZnO material is an efficient electrode material for high-performance supercapacitors. (C) 2019 Elsevier Ltd. All rights reserved.