RESUMO
The palladium nanoparticle (Pd NP)-decorated LaAlO3 /SrTiO3 (LAO/STO) heterostructure is for the first time used as a hydrogen-gas sensor with very high sensitivity and workability at room temperature. The outstanding gas-sensing properties are due to the Pd NPs' catalytic effect to different gases, resulting in charge coupling between the gas molecules and the two-dimensional electron gas (2DEG) through the Pd NPs by either a direct charge exchange or a change of the electron affinity. These results provide insight into the emerging properties at LAO/STO interfaces.
RESUMO
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 WO3 film is found to be constructed of WO3 nanoclusters of diameters of 3-5 nm. The nanoclusters are loosely connected to form a structure of high porosity around 66%. With this structure, the film exhibits many excellent room-temperature H2 sensing properties, including high sensitivity, broad detectable range of H2 concentration, 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 H2 sensors for monitoring the leakage of H2 and ensuring safe use of this gas.
