The research of lead ion detection based on rGO/g-C3N4 modified glassy carbon electrode

Abstract

Lead-ion (Pb2+) electrochemical sensors were prepared by modified reduced graphene oxide (rGO)/graphite nitride carbon (g-C3N4) nanosheet composite (rGO/g-C3N4) on the surface of glassy carbon electrode (GC). RGO/g-C3N4 composite was prepared by a simple thermal polycondensation process and reduction of hydrationhydrazine method. The as-prepared composite samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), fourier transform infrared (FT-IR),X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller (BET). It is concluded that the GC electrode modified by rGO/g-C3N4 had better electrochemical performance, higher sensitivity and selectivity in Pb2+ detection. Under optimized experimental conditions, there was a linear relationship between the square wave anode stripping voltammetry (SWASV) currents and the concentration of Pb2+(0.01–1000 nmol/L) with the limit of detection (LOD) was 1.07 × 10-12 mol/L (Signal-to-noise ratio is 3). In addition, the recovery experiment of Pb2+ in the practical samples was determined by standard addition method, which was consistent with the results obtained by atomic absorption spectrometry (AAS) method.