Fabrication of palladium-zinc oxide-reduced graphene oxide hybrid for hydrogen gas detection at low working temperature

This paper demonstrates a hydrogen gas sensor based on palladium-zinc oxide-reduced graphene oxide (Pd-ZnO/RGO) ternary hybrid via hydrothermal route. The nanostructures of Pd-ZnO/RGO hybrid nanocomposites were fully characterized by scanning electron microscopy and X-ray diffraction, confirming its successful preparation. The Pd-ZnO/RGO hybrid film sensor was investigated by exposing to hydrogen gas with concentration in a wide range of from 1 ppb to 500 ppm. The experiment results exhibit that the presented sensor has a hypersensitive response, quite short response/recovery times, and achieves ppb-level ultralow detection toward hydrogen at low working temperature. The underlying sensing mechanism of the Pd-ZnO/RGO hybrid toward hydrogen was attributed to the synergistic effect of the ternary hybrid nanomaterials and the modulation of the depletion layer width at the interfaces. This work indicates that the ternary Pd-ZnO/RGO hybrid is a candidate for constructing highperformance hydrogen gas sensors for various applications.