Room temperature hydrogen sensing with the graphite/ZnO nanorod junctions decorated with Pt nanoparticles

We report on the performance of solution-processed hydrogen sensors based on vertical arrays of ZnO nanorods with Schottky contacts. The vertical arrays of ZnO nanorods are grown by a low temperature hydrothermal method on a seed layer consisting of electrophoretically deposited ZnO nanoparticles. A Schottky contact on the ZnO nanorod arrays is created by the deposition of graphite from a colloidal solution. The structure of the graphite/ZnO nanorod system is shown to be sensitive to hydrogen at room temperature. The hydrogen sensing properties are further enhanced by the decoration of the graphite/ZnO nanorod interface with Pt nanoparticles. The sensing response is improved by a factor of 100, and faster recovery and response times are observed.