A chemoresistive hydrogen gas sensor prepared by a sputtered indium tungsten oxide thin film and palladium nanoparticles

Abstract

A new chemoresistive hydrogen (H₂) gas sensor, incorporated by a radio frequency (RF) sputtered indium tungsten oxide (IWO) thin film and evaporated palladium nanoparticles (Pd NPs), is produced and studied in this work. The employed Pd NPs enhance the catalytic activity towards H₂ gas due to their larger effective surface area, thereby improving the gas sensing performance. Various characterization techniques are used for structural, elemental, and compositional analyses. Gas measurements are conducted at 100 °C under various H₂ gas concentrations. In an environment of 1% H₂/air, the sensor exhibits a high sensing response of 1.8 × 10⁶ with a response time of 88 s and a recovery time of 13 s at 100 °C. The device also demonstrates promised repeatability, long-term (180 days) durability, and selectivity. The influences of relative humidity RH(%) on the H₂ gas sensing properties are studied in this work. Furthermore, the sensor shows advantages in terms of simple structure, ease of fabrication, and low cost.