Preparation Of Hierarchical Indium Oxide Nanomaterials And Research On Enhanced Gas Sensing Performance

In recent years,with the rapid development of society and economy,people's living standards have been continuously improved,and industrialized enterprises have spread all over the country.The resulting toxic and harmful gases have caused a serious threat to the environment around us,and air pollution has become more and more serious.In order to ensure the safety of people's lives and properties,we urgently need a sensor that can accurately detect toxic and harmful gases in the environment.As a result,the gas sensor has slowly entered people's sight.The application range of the gas sensor is very wide.It can be used in the detection of chemical weapons,pollution sources and toxic gases.The metal oxide semiconductor gas sensor has simple operation.The advantages of low manufacturing cost,good stability and high sensitivity have attracted wide attention.Among the many oxides,In₂O₃is a new type of N-type semiconductor material that has received widespread attention.Compared with other materials,it has the advantages of wider band gap and high sensitivity,so it has applications in various fields.However,continuous research has shown that In₂O₃also has its shortcomings,such as the shortcomings of high operating temperature,which limits the scope of its application.Hierarchical nanomaterials refer to materials of micron and above scales that are formed by self-organization or directional growth of nano-scale particles through self-organization or directional growth,and then form a special ordered structure through a certain function,which can give a large amount of gas transmission and diffusion to sensitive materials.Space,and a large number of gas adsorption and surface active sites.A large number of studies have shown that the hierarchical structure can improve the sensing performance of the material and has a great potential for development.This paper mainly uses simple hydrothermal synthesis to prepare indium oxide gas-sensitive materials with hierarchical structure,and further uses methods such as element doping and surface loading of nanoparticles to improve its sensitivity.The main research contents are as follows:(1)The hierarchical structure of indium oxide gas-sensitive material is prepared by hydrothermal method.First,different sulfur sources are used to prepare several indium sulfide with hierarchical structure.The obtained products are characterized by field emission scanning electron microscopy(FESEM)and X-ray diffraction analysis(XRD)analysis methods.After determining the preparation plan,Then through high temperature calcination,the hierarchical structure of indium oxide is finally obtained,and its structure is characterized and analyzed,and its gas sensitivity performance is tested.(2)The hierarchical structure of indium oxide bulbs doped with Zn and Cd are prepared by hydrothermal method.Through a series of characterization and microscopic tests on the obtained material,the results show that the doped indium oxide spheres are uniform in size and regular in appearance.It also shows excellent gas sensitivity to triethylamine.Compared with pure indium oxide,the gas sensitivity of doped indium oxide has been greatly improved.Based on the characterization results,the mechanism of element doping to improve gas sensitivity is discussed and analyzed.(3)The hierarchical structure indium oxide gas-sensitive material of composite ruthenium oxide is prepared by hydrothermal method.The microscopic test of the obtained composite material found that the prepared indium oxide has a curd shape,the surface is self-assembled and grown by nanosheets,and the curd has a uniform size and regular morphology.Through the gas sensitivity test,the best working temperature is 240?,and it has a good response performance to triethylamine.The mechanism of improving the gas sensitivity of composite materials is analyzed and discussed.(4)On the surface of hierarchical structure indium oxide spheres,precious metal gold nanoparticles were loaded to prepare Au@In₂O₃composite material.Through a series of characterization analysis of the obtained product,it can be seen that Au nanoparticles are uniformly distributed on the surface of the indium oxide curd.Based on the catalytic effect of Au nanoparticles,the sensitivity of the composite material to triethylamine gas has been significantly improved.