Palladium (Pd)-based hydrogen (H2) gas sensors have been widely investigated thanks to its fast reaction and high sensitivity to hydrogen. Various sensing mechanisms have been adopted for H2 gas sensors; however, triboelectric hydrogen gas sensing has not been much investigated to date. We report here H2 gas sensor that can detect H2 by measuring the output voltages generated during contact electrification between two friction surfaces. When two dielectric surfaces on metal electrode are periodically contacted and released, each surface is electrified due to charge separation between two surfaces. The one surface gained electrons is charged negatively, while the other surface lost electrons is positively charged, depending on their difference in electron affinity. Here, when the H2 sensor, composed of Pd-coated ITO and PET film, is exposed to H2, its output voltage is varied in proportion to H2 concentration because the work function (WF) of Pd-coated surface changes, altering triboelectric charging behavior of the functionalized surface. Specifically, the output voltage of the sensor is gradually increased as the exposing H2 concentration increases. Using this sensor, sensor response, sensitivity, response and recovery of triboelectric hydrogen gas sensor were investigated. Reproducible and sensitive sensor response was observed up 1% H2 exposure. The approach introduced here can be easily adopted for development of triboelectric gas sensors detecting other gas species.

Triboelectric hydrogen gas detection using palladium functionalized surface

253rd National Meeting (2017)

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