Research On Compound Semiconductor Oxide Gas Sensor For Detection Of Exhaled Gas Markers

With the advancement of technology and the improvement of living standards,people pay more and more attention to their health status.In recent years,disease markers in breath have been gradually discovered and confirmed,providing a new opportunity for the development of new non-invasive disease diagnosis technology foundation.In all kinds of gas detection technology,semiconductor metal oxide?SMO?gas sensors have the advantages of stable structure,high sensitivity,fast response recovery speed,and low price.They show attractive application prospects in detecting breath biomarkers.But SMO gas sensors generally work at higher temperatures,and the ability to identify low-concentration gases cannot meet the requirements of breath detection.In view of the above problems,this article mainly prepared WO₃ composite gas sensors and new types of metal-organic framework?MOF?-driven precious metal nanoparticle-sensitized gas sensors from the perspective of the design of new sensitizers to improve the performance of SMO devices.In₂O₃ composite gas sensor sensitized by two-dimensional material MXene.The rational design of the sensitizer improves the performance of the sensor and enables the detection of gas markers in exhalation.The specific results are as follows:?1?In this work,three-dimensional inverse opal?3D inverse opal,3DIO?WO₃structure modified with metal-organic frameworks?MOF?derived ZnO@Au NPs were designed and fabricated for trace H2S detection.The ordered macroporous structure of3DIO with large surface areas,the formation of n-n heterojunctions between WO₃ and ZnO,and the effective encapsulated of small-sized Au NPs benefited the enhancement of the sensing performance.Compared to the pristine 3DIO WO₃ sensor,the response of MOF derived 3DIO WO₃/ZnO@Au sensor enhances 6.5-folds?175 to 10 ppm H₂S?,the optimal working temperature dramatically decreases from 375·C to 170·C,and the actual detection limit extends to 50 ppb.Moreover,the MOF derived 3DIO WO₃/ZnO@Au sensor also has good stability and selectivity.Theoretical simulations indicate that the increase in conductivity,the increase in the negative charge of O,and the increase in adsorption energy may be the main reasons for improving the selectivity of the device.In addition,the sensor can distinguish the change of H₂S concentration in simulated exhaled gas.This work demonstrates an example of a simple and versatile method for high performance H₂S gas sensor design,which is promising for applying in the exhaled breath biomarker determination.?2?Designed and fabricated Ti₃C₂T_x and In₂O₃ nanowire composite room temperature gas sensor.We first synthesized In₂O₃ nanowires by electrostatic spinning,and then etched Ti₃AlC₂ to obtain a few layers of Ti₃C₂T_x nanosheets.We load In₂O₃nanowires on Ti₃C₂T_x and perform a series of gas detection at room temperature.Because Ti₃C₂T_x has a very high signal-to-noise ratio when performing gas detection,even if the gas response is very low,it can clearly distinguish low-concentration gases.We think that this kind of sensor has a good development prospect for the detection of exhaled biomarkers at room temperature.