A Hydrogen Peroxide Electrochemical Sensor Based on Core-Shell MnO 2 -SiO 2 -Ag Nanocomposite

Abstract

A core-shell nanocomposite of manganese dioxide-silicon dioxide-silver nanoparticles (MnO 2 -SiO 2 -Ag) was synthesized via hierarchical assembly successfully and further fabricated in an electrochemical sensor of hydrogen peroxide (H 2 O 2). The composites were characterized by transmission electron microscope (TEM), X-ray diffractometer (XRD), UV-visible spectroscopy and Fourier transform infrared spectrum (FTIR). The electrochemical investigation conducted by cyclic voltammetry, electrochemical impedance spectroscopy and chronoamperometry, reveals that the composites have excellent catalytic property toward H 2 O 2. The sensor could detect H 2 O 2 with a wide linear range from 2.0 μmol · L -1 to 8.86 mmol · L -1 and a low detection limit of 0.7 μmol · L -1 in N 2 -saturated phosphate buffer solution (PBS, pH 7.2). The sensor also shows reproducible and good stability. The study indicates MnO 2 -SiO 2 -Ag nanocomposite has great potential in the further practical applications. © 2014 The Electrochemical Society. All rights reserved.