Hydrogen Sensing Properties of a Tin Dioxide Thin Film Incorporated with Evaporated Palladium Nanoparticles

This work demonstrates a new hydrogen gas sensor prepared by a radio-frequency (RF) sputtered tin dioxide (SnO2) thin film and palladium (Pd) nanoparticles (NPs). The related hydrogen gas sensing properties are comprehensively studied in this work. Materials characterizations were conducted by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), energy-dispersive X-ray spectroscopy (EDS), high-resolution scanning electron microscopy (HRSEM), and transmission electron microscopy (TEM). The employed Pd NPs greatly enlarge the surface area/volume (SA/V) ratio and enhance the catalytic activity of Pd metal. A significantly high sensing response of 1.31 105 under introduced 1000 ppm H2/air gas with a response (recovery) time of 81 s (11 s) and a lower detecting concentration of 10 ppb H2/air at 125 °C were acquired for the studied Pd NP/SnO2 device; as well, the studied sensor device could be operated at a lower temperature (25 °C). In addition, the studied device shows excellent selectivity and long-term stability in regard to hydrogen gas. On the basis of advantages above-mentioned and benefits of a relatively simple structure, ease of fabrication, low cost, and lower power consumption, the proposed device propitious for hydrogen gas detection.