Room-temperature resistive H₂sensing response of Pd/WO₃nanocluster-based highly porous film

Hydrogen- (H2-) induced resistive response of palladium (Pd) coated tungsten oxide (WO3) films prepared by using supersonic cluster beam deposition (SCBD) was investigated. An SCBD WO3film is found to be constructed of WO3nanoclusters of diameters of 3-5nm. The nanoclusters are loosely connected to form a structure of high porosity around 66%. With this structure, the film exhibits many excellent room-temperature H2sensing properties, including high sensitivity, broad detectable range of H2concentration, low detection limit, fast response rate, excellent cyclic stability (>2400 cycles), high selectivity against vapor of many organic compounds, mild ambient pressure dependence and many other advantages such as low power consumption, miniaturizability and high batch-to-batch reproducibility. These findings are useful for making new high-quality H2sensors for monitoring the leakage of H2and ensuring safe use of this gas.