Abstract
•Pt-WO3 nanorods are synthesized via hydrothermal and chemical reduction method.•The sensor based on Pt-WO3 shows excellent comprehensive performance with high sensitivity and fast response/recovery speed.•The minimum detection limit of Pt-WO3 based sensors to H2S was as low as 5 ppb.•The electron sensitization and chemical catalysis of Pt nanoparticles greatly enhanced the gas sensing properties of WO3.
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The Pt-loaded WO3 materials have been synthesized via simple hydrothermal and chemical reduction methods. The microstructure of prepared Pt-WO3 exhibits as nanorods consisting of bundles of finer nanorods and the Pt nanoparticles with a size of ca. 5 nm loaded on the surface of WO3. The gas sensing measurements of Pt-WO3 material show excellent gas sensing selectivity to H2S compared with many other pollution gases (e.g. NO2, SO2, NH3, CO and CO2). In particular, 0.2 at% Pt-WO3 exhibits extremely high response (1638–10 ppm H2S), short response/recovery time (42 s/37 s) and low detection limit (1.27–5 ppb H2S) at 200 °C. The superior performance of 0.2 at% Pt-WO3 compared with pure WO3 mainly originate from its modulating action to conductive band electrons of WO3 and its catalysis to the chemisorption reaction on the surface.