▎ 摘　　要

A novel nonenzymatic H2O2 sensor based on a palladium nanoparticles/graphene (Pd-NPs/GN) hybrid nanostructures composite film modified glassy carbon electrode (GCE) was reported. The composites of graphene (GN) decorated with Pd nanoparticles have been prepared by simultaneously reducing graphite oxide (GO) and K2PdCl4 in one pot. The Pd-NPs were intended to enlarge the interplanar spacing of graphene nanosheets and were well dispersed on the surface or completely embedded into few-layer GN, which maintain their high surface area and prevent GN from aggregating. XPS analysis indicated that the surface Pd atoms are negatively charged, favoring the reduction process of H2O2. Moreover, the Pd-NPs/GN/GCE could remarkably decrease the overpotential and enhance the electron-transfer rate due to the good contact between Pd-NPs and GN sheets, and Pd-NPs have high catalytical effect for H2O2 reduction. Amperometric measurements allow observation of the electrochemical reduction of H2O2 at 0.5V (vs. Ag/AgCl). The H2O2 reduction current is linear to its concentration in the range from 1x10(-9) to 2x10(-3)M, and the detection limit was found to be 2x10(-10)M (S/N=3). The as-prepared nonenzymatic H2O2 sensor exhibits excellent repeatability, selectivity and long-term stability.