Structural Regulation And Gas Sensing Performance Studies Of Indium Oxide Nanomaterials

Indium oxide(In2O3)is a typical n-type semiconductor gas-sensing material.How to effectively improve the gas-sensing performance of In2O3 has attracted much attention.The main factors affecting the gas-sensing properties of materials are structural and chemical composition.Structure and chemical composition affect the gas-sensing properties by affecting the content of chemisorbed oxygen on the surface and the material's conductive layer.Hydrogen treatment can adjust the defect structure of In2O3 and change the carrier mobility and concentration of the material,which is conducive to the formation of more chemisorbed oxygen.In this paper,the influence of bulk and surface defect structure on gas-sensing properties was studied by preparing hydrogen reduction treatmented In2O3 nanoparticles for different times and the flower-like In2O3 materials doped with different transition metal elements(Ni,Cu,Zn).The details are as follows:1.Hydrogen-treated In2O3 nanoparticles were prepared at different times and their gas-sensing properties were evaluated.The results show that hydrogen treatment can improve the response of In2O3 nanoparticles to formaldehyde gas.The gas response of In2O3-H10 to 100 ppm formaldehyde at 230 0C is 80,which is higher than that of In2O3 without hydrogen treatment.The results of material characterization show that the hydrogen treatment increases the content of bulk oxygen vacancies(VO),changes the carrier mobility and concentration,and facilitates the formation of chemisorbed oxygen on the surface of the material.And then improve its gas-sensing response to formaldehyde.At the same time,it also provides some new insights into the influence of surface or bulk VO on gas sensing performance.2.The flower-like In2O3 materials doped with different elements(Ni,Cu,Zn)and content(1%,3%,5%)were prepared by hydrothermal method.The study of its gas sensing properties shows that the optimum doping content,the optimal operating temperature and the gas response of different element doped In2O3 are different.Compared with pure flower-like In2O3,element doping significantly increases the response to formaldehyde,and Zn doping reduces the operating temperature of formaldehyde.