Hydrogen sensor based on graphene/ZnO nanocomposite

a b s t r a c t Graphene/zinc oxide (ZnO) nanocomposite was prepared by in situ reduction of zinc acetate ((CH3COO)2Zn·2H2O) and graphene oxide (GO) during refluxing. For the structural, morphological and elemental analysis, the synthesized samples were characterized by X-ray diffraction (XRD), field emis- sion scanning electron microscopy (FESEM), energy dispersive X-ray analysis (EDX) and Fourier transform infrared spectroscopy (FTIR). Hydrogen sensing properties of synthesized graphene/ZnO nanocomposite have been reported in this paper. For gas sensing properties, thick films of synthesized nanocompos- ite powder were fabricated on alumina substrate. Sensing results revealed that sensor based on 1.2 wt% graphene/ZnO composite exhibits best sensing response towards 200 ppm of hydrogen gas at an optimum operable temperature of 150 ◦ C among the prepared samples with varying concentrations. Inclusion of graphene into ZnO significantly reduced the optimum operable temperature and increased the sensing response of graphene/ZnO composite towards hydrogen gas. Reported results are based on the change in electrical conductivity of synthesized nanocomposites due to superior electronic conductivity of graphene and the interaction between p-type graphene and n-type zinc oxide.