Research On The Acetone Sensing Properties And Mechanism Of Ru-WO₃ Modified By Metals

Acetone in exhaled gas air of human body can be used as an important physiological marker of diabetes mellitus,some new requirements are put forward for exhalation analysis acetone detection technology to rapidly distinguish healthy and sick people.Metal oxide semiconductor gas sensors have the advantages of simple preparation process,low cost,small volume and high stability,which is suitable for application in miniaturized,online rapid detection equipment,and the key to the development of related high-performance medical equipment technology.Tungsten trioxide has great prospects in gas detection due to its advantages of simple process and great sensing performance.Ruthenium-loaded WO₃obviously improves the gas sensitivity to acetone and becomes an important choice for detecting acetone vapor.In this paper,metals are continuously loaded on the surface of Ru-loaded WO₃ material to improve the sensitivity,selectivity to acetone vapor and its anti-interference capability.In this paper,the WO₃ nanoparticles were prepared by thermal decomposition method,Ru-loaded WO₃ and metal-loaded Ru-WO₃ were prepared by mother liquor method,and the planar thick film gas sensor was prepared by screen-printed technology.The XRD,SEM,TEM,XPS,and TPR methods were used to analyzed WO₃ and metal-loaded WO₃nanoparticles.The sensing properties and the stability of WO₃ and metal-loaded WO₃ were characterized by the dynamic gas distribution test system.Based on the relationship between the sensor resistance and oxygen partial pressure in different atmospheres,the sensitization mechanism of the sensors to acetone was explored.It was showed that the prepared WO₃ nanoparticles belong to monoclinic crystal phase and have larger mesoporous structure.The loaded metals had no obvious effect to the surface morphology and mesoporous structure of WO₃ nanoparticles,and noble metals showed different chemical states on WO₃ surface.The results showed that the metals loading obviously improved the gas sensing response of WO₃ to acetone and the anti-interference capability.With the increase of loading amount,the gas sensing performance of the sensor to acetone first increases and then decreases.The sensing performance of the sensor was affected by working temperature,with the working temperature increasing,the sensing performance of WO₃ was enhanced,while the metal-loaded WO₃ was first enhanced and then decreased.The sensors has good stability at working conditions for a long time.The gas sensing mechanism to acetone has changed after metal loading on WO₃ surface.The p-n junction between PtO₂ and WO₃ extends the space charge region on the surface of Pt/Ru-WO₃,and the redox reaction between Ptnanoparticles and acetone has promoted the sensing response.The electronic coupling between Rh₂O₃ and WO₃ has enhanced the gas sensing properties on the surface of Rh/Ru-WO₃.The metal-loaded Ru-WO₃ has improved the gas sensing response and its anti-interference capability to acetone,and provides theoretical and practical guidance for its further application in exhalation analysis acetone system.