The Preparation Of Molybdenum Trioxide And Gas Sensing Performance Of The Gas Sensor

With the development of the industry progress and the society,the harmful gases are influencing people around the world more and more.As one of the most harmful gases,xylene is used in each zone widely.Even inhalation of microscale of xylene gas can cause enormous hurt to body.Unwittingly oral of xylene can cause deadly disease such as acute pneumonia and cancer.It's important that how to detect and prevent the discharge of harmful gases.The gas sensor can detect the concentration of the harmful gases and turn the concentration into the electrical signal.The gas sensors can be classified into plenty of methods.Related to other kinds of gases sensors,the semi-conductive type of gases sensors achieves more attention by the advantages such as portability,higher response,rapid response and recovery time.The performance of this kind of gas sensors depends on if the materials on the gas sensors has a good performance of the text gas from a very large extent.Nano-materials have widely use in the semi-conductive gas sensors.In the traditional sense,the nano-materials can be divided into one-dimensional nano-material,two-dimensional nano-material and zero-dimensional nano-material.Recently three-dimensional nano-material were included into nano-materials.Nano-materials have some unique effects such as quantum tunneling effect,volume effect and so on.It would be hot point that how to take the advantage of the nano-materials to promote the development of the gas sensor.There are many methods to prepare nano-materials.The facile hydrothermal method become the most popular method to prepare the nano-materials by its advantages of easy equipment requirement,low cost,high productivity,high crystal integrity.In this study,?-MoO₃ nanobelts were prepared and the nano-materials were decorated to improve the performance of the gas sensors based on the nano-materials.The details of the study as follows:?1?Optimum experiment condition of synthesizing ?-MoO₃ nanobelts was researched via hydrothermal method,and the xylene gas sensors were made.The gas sensors based on ?-MoO₃ nanobelts performed high response,fast response time and had a low working temperature.?2??-MoO₃ nanobelts were decorated by ?-Fe2O₃ via hydrothermal method,?-MoO₃ nanobelts were successfully covered by stab-like ?-Fe2O₃ and formed heterojunction.Then the performance of the gas sensor based on ?-MoO₃/?-Fe2O₃ heterojunction were texted,the response were enhanced from 2.9 to 6.9,the selectivity were enhanced signally.?3?Prepared gas sensors based on Zr doped ?-MoO₃ nano-materials and characterization analysis were made.Then the performance of the gas sensor based on Zr doped ?-MoO₃ nano-materials were texted,the response were enhanced from 2.9 to 7.9.?4?The mechanisms were explained by the theory of heterojunction and metal element doping,respectively.In the paper,the XRD,SEM,TEM,EDX characterization analysis were made.