Study of a Palladium Nanoparticle/Indium Oxide-Based Hydrogen Gas Sensor.

An interesting hydrogen (H2) gas sensor, synthesized by an indium oxide (In2O3) layer and evaporated palladium (Pd) nanoparticles (NPs), is manufactured and studied. The utilized Pd NPs essentially enhance the surface area/volume (${S}_{A}/{V})$ ratio and catalytic reactivity of the Pd metal. Energy-dispersive X-ray spectroscopy (EDS), atomic force microscopy (AFM), high-resolution scanning electron microscopy (HRSEM), and TEM were used to investigate the relevant material behaviors of the proposed Pd NP/In2O3 sensor device. The sensing mechanism is explicated in this study. A very high-sensing response of 5243 under 1% H2/air gas with a response time of 12 s and an extremely low-detecting content of 100 ppb H2/air were obtained at the optimal operating temperature of 225 °C. In addition, excellent selectivity toward hydrogen gas is observed for the studied device. The proposed sensor also shows advantages of simple structure, low-cost, and relatively easy fabrication process. [ABSTRACT FROM AUTHOR]