Ammonia sensing performance of a platinum nanoparticle-decorated tungsten trioxide gas sensor

Abstract Platinum nanoparticles (Pt NPs) are decorated on a sputtered tungsten tri-oxide (WO 3 ) thin film to fabricate a high-performance ammonia gas sensor. These Pt NPs are synthesized by drop coating combined with UV irradiation approaches. Compared to a sensor comprising pristine WO 3 thin film, the studied Pt NP/WO 3 device shows a significant improvement in ammonia sensing response. The experimental results indicate that a high sensing response of 26.9 is measured under 1000 ppm NH 3 /air gas at 250 °C. Furthermore, even at a low concentration of 1 ppm NH 3 /air, a good sensing response of 3.73 is acquired from this device. The superior performance is attributed mainly to the catalytic activity and increased surface-to-volume ratio of Pt NPs. The relevant ammonia sensing properties and thermodynamic characteristics are also investigated. In addition, the Pt NP/WO 3 device demonstrated in this study has advantages including a simple structure, low cost, a relatively easy fabrication process, and a wide concentration detection range.