Noble metal-free modified electrode of exfoliated graphitic carbon nitride/ZnO nanosheets for highly efficient hydrogen peroxide sensing

Graphitic carbon nitride (g-C3N4)/ZnO nanosheets were coated on the surface of fluorine-doped tin oxide (FTO) glass as a noble metal-free g-C3N4/ZnO/FTO electrode, which was used for the determination of hydrogen peroxide (H2O2). The exfoliated g-C3N4 nanosheets were firstly prepared and then ZnO nanosheets were grown on g-C3N4 nanosheets by a microwave-assisted hydrothermal synthesis. The g-C3N4 nanosheets combined with ZnO nanosheets can greatly improve the adsorption of hydrogen peroxide and increase the conductivity of materials as well. The g-C3N4/ZnO nanosheets were characterized by powder X-ray diffraction (XRD), scanning electron microscopic (SEM), transmission electron microscopic (TEM), and X-ray photoelectron spectroscopy (XPS) analysis. Meanwhile, electrochemical measurements of the g-C3N4/ZnO/FTO electrode were utilized to investigate the amperometric sensing of hydrogen peroxide. The prepared g-C3N4/ZnO/FTO electrode revealed the sensitivity of 540.8 mu A mM (1)cm (2) at -0.5 V with the linear response range from 0.05 to 14.15 mM, which even was superior to some noble metal-decorated H2O2 sensors. Additionally, the g-C3N4/ZnO/FTO electrode also showed the reliable operational and environmental stability for electrochemical reduction of H2O2. (C) 2017 Elsevier Ltd. All rights reserved.