Enhanced Sensing Performance Of Adsorption Gas Sensor Based On Mesoporous SnO₂

In recent years, the rapid and real-time detection to the pollution gas plays anincreasingly important role with the gradually air pollution. For this reason, thehigh-Performance gas sensor is urgently needed. In order to satisfy the requirement ofdetecting low concentration pollution gases, the response and detection limit of thegas sensor should be improved significantly. Concerning this issue, not only thedevelopment of the sensor material, but also the explorations of the device structureand pulse method are needed.The mesoporous material, with various pore structures and ordered mesoporousstructures, is widely used for gas sensor, catalyst, lithium battery and solar cells andother important fields. As a gas sensor, the characteristic of the mesoporous materialscontributes to the gas diffusion of the sensor. In addition, mesoporous materials havelarge surface area, which can which can provide more active sites and facilitated thereaction on the sensitive materials.As a new driving method of gas sensor, the pulse driving has two differentoperating temperatures for detecting: the low temperature is used to absorb andconcentrate more target gas; the high temperature is used to detect the gas absorbed atlow temperature. Combined with the absorbability advantage of mesoporous materialand pulse driving method, it can further improve the response of the lowconcentration gas, which can be fabricated new enhanced adsorption sensor.In the first chapter, we have outlined two aspects of the mesoporous material andthe gas sensor. The paper has introduced the formation mechanism, synthetic method and application of the mesoporous material, the classification of the gas sensor, thebenefits of semiconductor gas sensors and two different structures of gas sensor. Inthe end, the paper has briefly indicated the structure and properties of SnO2as well.In the second chapter, the ordered mesoporous SnO2have been successfullysynthesized via nanocasting method with the mesoporous silicon oxide SBA-15ashard template, and the best optimum preparation conditions has been investigated.The mesoporous SnO2show order mesoporous structures and large surface area bymaterial characterization.In the third chapter, on the basis of chapter two, the Ag element is loaded in themesoporous SnO2via equal volume impregnation. A study on their gas sensingproperties for H2S with both pulse driving and constant driving has been investigated.The sharply enhance response of H2S is arisen from the Ag2O loading and the gassensor with pulse driving can detect lower concentration of H2S, as low as50ppb,which shows high stability and good selectivity.In the fourth chapter, the CuO/SnO2sensor material have been synthesized viadirect doping. A study on their gas sensing properties for H2S with both pulse drivingand constant driving has been investigated. The experiments show that the CuO/SnO2sensor has good response to H2S and the sensor with pulse driving can increase theresponse of H2S.In this paper, we have systematically studied the design of the enhancedadsorption sensor. We have dramatically improved adsorption capacity of the gas onthe surface of the material to improve the response of the sensor by the synthesis ofthe mesoporous sensitive material, the noble metals loading, and the pulse drivingmethod. We look forward to providing a new strategy to detect lower gas and improve the response of the sensor.