Research On Gas Sensor Stem From Micro-nano Structure Indium Oxide

Nowadays,the development of science and technology is showing a trend of rapid progress,affecting the development of various industries,making people’s lives gradually enter the era of interconnected things.Sensors,as the"sensory system"in the interconnection of all things,play a pivotal role in information acquisition.The development of the sensor industry also affects the comprehensive national strength,so vigorously developing sensor technology is of great significance.Gas sensors,as one of the important branches,have a place in fields such as daily life production,transportation,aviation,and aerospace.Compared with large-scale gas measurement instruments such as spectroscopy,chromatography,and mass spectrometry,gas sensors stand out due to their advantages such as small size,low power consumption,and easy integration.Semiconductor gas sensors have become a mainstream research hotspot in the field of gas sensors due to their excellent gas sensing performance,convenient preparation methods,and simple device structures.Given the advantages of semiconductor gas sensors,this project aims to develop new gas sensors for the detection of flammable,explosive,and industrial polluting gases.Indium oxide（In₂O₃）as a new gas sensing material has become the research topic of this thesis.The specific research content is as follows:1.Lichee-like g-C₃N₄/In₂O₃ were successfully prepared by hydrothermal method,the gas sensors were constructed and evaluated.The nanostructures and chemical compositions of g-C₃N₄/In₂O₃ were characterized by XRD,SEM,TEM,and XPS.The performance of the 3 wt%g-C₃N₄/In₂O₃ sensor exhibits good gas-sensing properties,with response value of 180%to 100 ppm H₂ at 275℃,fast response/recovery time（2s/2.4s）,excellent selectivity and good stability.The sensitization mechanism was discussed.2.Flower-like Au/In₂O₃ was successfully developed by wet impregnation,a series of gas sensors were prepared and evaluated.Morphology and composition of Au/In₂O₃were characterized by XRD,SEM,TEM,and XPS.The 0.5 mol%Au/In₂O₃ sensor has a response value of 1624 to 1 ppm NO₂ at 100℃,lower detection limit（10.4 to 10 ppb NO₂）,good selectivity and reliable repeatability.Finally,the sensitization mechanism of Au/In₂O₃ was analyzed and discussed.