Enhanced ammonia detection of gas sensors based on square-like tungsten oxide loaded by Pt nanoparticles

Square-like tungsten oxide submicron materials were successfully synthesized via a simple hydrothermal route. It is found that the morphology, size and crystal structure of the products can be conveniently controlled by simply adjusting the reaction time and reaction temperature in the solution system. When used as the gas-sensing materials, the tungsten trioxide sensors show excellent responses to ammonia. Pt-loaded square-like WO3 can significantly improve the responses, and we also found that the Pt mass contents were configured to 1 wt% can realize the tallest response among the square-like WO3 and Pt-loaded WO3 for ammonia and other organic vapors. The experimental results indicate that a high sensing response of 100.09 is measured under 1000 ppm NH3/ air gas at 270 degrees C. Furthermore, even at a low concentration of 1 ppm NH3/air, a good sensing response of 1.12 is acquired from this device. Moreover, responses with change in relative humidity from 10% to 90% were also investigated. Long-term stability test exhibits the gas sensor have good stability. The mechanism of enhanced sensor performance is also discussed. In addition, the gas sensor device demonstrated in this study has advantages including a relatively easy fabrication process, a simple structure, low cost, and a wide concentration detection range.

Automated summary

Square-like tungsten oxide submicron materials were successfully synthesized via a simple hydrothermal route, with controlled morphology, size, and crystal structure. Tungsten trioxide sensors showed excellent responses to ammonia, while Pt-loaded square-like WO3 significantly improved the responses, particularly at 1 wt% Pt mass content.