Synthesis Of WO₃Nanomaterials And Its Gas-Sening Properties

Semiconductor gas sensors have been researched for many years, which are attracted considerable attention in a variety of fields such as industrial waste gas detection, civil life security and diagnosis of diseases. Despite many significant results have been obtained, many problems should be solved in the region of the gas sensors, such as relatively low response and selectivity and high cost, which limits their application.In this dissertation, considering the size effect and p-n heterostructure to enhance the gas-sensing properties, WO3nanomaterials with high response, excellent selectivity and low cost for acetone and H2S were synthesized via liquid phase method. Furthermore, the gas sensors were fabricated. The main contents can be described as follows:(1) We described a simple, inexpensive and practical sol-gel process for the preparation of the γ and ε compound phase of WO3nanoparticles with23nm mean diameter and fabricated the acetone sensors based on this nanomaterial. These sensors show remarkable selectivity and good stability. More importantly, the response is as high as15.05in10ppm acetone with γ s response-time and12s recovery-time. Given the simple solution process of WO3nanoparticles and good sensing performance, our device is promising for the application in breath diagnosis of diabetes.(2) The different proportions of WO3/CuO p-n junction nanocomposites were synthesized by twice hydrothermal methods, and the growth mechanism was discussed. Then, the WO3/CuO p-n junction nanocomposite gas sensors were fabricated. The research results show that the gas-sensing properties of the nanocomposite is best when the ratio of Cu to W reaches100:5. And, its reponse is as high as334in10ppm H2S atmosphere at170℃, while it is not sensitive to500ppm of methanal, ethanol and acetone, rendering potential applications in environmental monitoring.