Graphene-Zirconium Oxide Nanoparticleshybrid is synthesized through a simple onestep hydrothermal route, where the reduction of GO and the in-situ generation of ZrO2 nanoparticles occurred simultaneously. Characterization of the resultant hybrid material using scanning electron microscopy (SEM),transmission electron microscopy (TEM), X-ray diffraction (XRD) and Raman spectroscopy clearly indicated the successful attachment and homogeneous dispersion of monodisperseZrO2 nanoparticles with particle sizes of ~5nm to graphene sheets. Potential cycling in CoCl2 natural aqueous solution was used for deposition of cobalt Oxide nanoparticles onto rG-ZrO2 nanocomposite. The formation of cobalt oxyhydroxide film was investigated by SEM and cyclic voltammetry in alkaline and natural aqueous solutions. The electrodeposition of cobalt oxide nanoparticles on the surface of rGZrO2nanocomposite appears to be a highly efficient method for the development of a new class of sensitive, stable and reproducible hydrogen peroxide electrochemical sensor. The response to H2O2 on the modified electrode was examined using cyclic voltammetry and amperometry. The amperometric detection of H2O2 is carried out at 0.35 V versus Ag/AgCl reference electrode in phosphate buffer solution with pH 7.4.
