Zinc Oxide Nanoparticles Decorated on Graphene Sheets@Cerium Oxide Nanocomposites to Sensitize Gold Electrode for the Nonenzymatic Hydrogen Peroxide Detection

A selective and sensitive nonenzymatic hydrogen peroxide (H2O2) electrochemical sensor was fabricated. It was based on zinc oxide (ZnO) nanoparticles decorated on core-shell structure graphene sheets@cerium oxide (GS@CeO2) nanocomposites sensitizing gold electrode (GE). The ZnO were homogenously decorated on the surface of GS@CeO2 nanocomposites via a facile solvothermal process. The X-ray powder diffractometer combined with Fourier transform infrared spectroscopy were used to characterize the compositions of hybrid nanomaterials. The Electrochemical impedance spectroscopy and Scanning electron microscopy were employed to study the interfacial properties and morphologies of different electrodes, respectively. The electrochemical properties of electrochemical sensor were investigated by means of Cyclic voltammetry (CV) and Chronoamperometry (i-t curve) methods. After all experimental parameters were optimized, the GS@CeO2-ZnO hybrid nanomaterials modifying GE (GE| GS@CeO2-ZnO) showed a good performance toward the electrocatalytic reduction of H2O2. The wide linear detection range of CV peaks from 2.0 x 10(-3) mM to 20.0 mM (R = 0.9981) and a low limit of detection of 1.1 x 10(-3) mM (S/N = 3) were achieved. The proposed electrochemical sensor was simple, quick, stable and reliable to quantitative determination of H2O2 in contact lens care solutions. (C) 2016 The Electrochemical Society. All rights reserved.