Preparation Of Tin-based Oxide Fibers And Its Gas Sensitive Characteristic

With the continuous progress and development of industry and technology,people's work and life become more convenient.At the same time,people pay more attention to the quality of life and health.However,the environmental pollution accompanying the rapid development of industry adds a shadow to people's healthy life.People are eager to breathe the healthy green gas,so it is very important to prepare the gas sensor which can be widely used to detect the dangerous gases emitted by the surrounding and family living environment,vehicles and air conditioners.With the development of the industrial Internet of Things,information that cannot be accurately sensed by human five senses can be transferred to us through the Internet of Things into electrical signals,a variety of gas sensors have been developed.The selectivity and sensitivity of gas sensors are increasingly required,efforts are being made to find more suitable gas sensitive materials with the desired properties.In recent years,MOS materials have been of interest to researchers for their ability to meet the requirements of cheap,stable,sensitive and selective high-performance gas sensors.Among them,the chemical and physical properties of gas sensitive materials based on tin oxide are very good and have been studied.After consulting the literature,it is found that SnO₂is widely used in gas sensors.Of course,there are some drawbacks.For example,the detection temperature is too high,selectivity is sometimes not high,low concentration detection is poor and so on.Therefore,in view of some shortcomings,the specific work of this thesis is as follows:(1)3%AgCl-SnO₂nanofibers were first prepared by electrostatic spinning.The morphology,composition and structure of the synthetic material were characterized by SEM,TEM,XRD and XPS,and the gas-sensitive performance was tested by gas-sensitive tester.The use of polyaniline makes the material more pleated and enhances the adsorption of gas.The 3%AgCl-SnO₂nanofibers gas sensor shows excellent selectivity,sensitivity and low temperature for H₂S gas.The detection of response value of 150? to 10ppm H₂S gas up to 65 is realized.(2)ZnO doped SnO₂nanofibers were synthesized by electrostatic spinning method,and then annealed in 600? air.The prepared materials were characterized by SEM,TEM,XRD and Raman.Finally,pure SnO₂nanofibers and the composite fiber were made into gas-sensitive devices for H₂S testing.The performance of SnO₂-ZnO gas sensor is 8 times higher than that of SnO₂gas sensor due to the heterogeneous junction between SnO₂and ZnO,the working temperature is about 40? lower than that of similar materials.