LAUSR

Abstract Graphitic carbon nitride (g-C 3 N 4 )/ZnO nanosheets were coated on the surface of fluorine-doped tin oxide (FTO) glass as a noble metal-free g-C 3 N 4 /ZnO/FTO electrode, which was used for the determination of hydrogen peroxide (H 2 O 2 ). The exfoliated g-C 3 N 4 nanosheets were firstly prepared and then ZnO nanosheets were grown on g-C 3 N 4 nanosheets by a microwave-assisted hydrothermal synthesis. The g-C 3 N 4 nanosheets combined with ZnO nanosheets can greatly improve the adsorption of hydrogen peroxide and increase the conductivity of materials as well. The g-C 3 N 4 /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-C 3 N 4 /ZnO/FTO electrode were utilized to investigate the amperometric sensing of hydrogen peroxide. The prepared g-C 3 N 4 /ZnO/FTO electrode revealed the sensitivity of 540.8 μA 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 H 2 O 2 sensors. Additionally, the g-C 3 N 4 /ZnO/FTO electrode also showed the reliable operational and environmental stability for electrochemical reduction of H 2 O 2 .