Preparation Of SnO₂ Modified Materials And Their Gas Sensing Properties To H₂S Products

In recent years,with the development of the industry,the content of toxic and combustible gases in the atmosphere has gradually increased,which has an increasing impact on the environment,people’s lives and property safety.Therefore,effective detection of toxic gases in the atmosphere has become the focus of research.Hydrogen sulfide（H₂S）is a colorless gas with rotten egg smell,soluble in water,ethanol and glycerol,its chemical properties are unstable,it can be oxidized in the air to sulfur dioxide（SO₂）,mixed with air and combustion will explode.H₂S is also an irritant gas,mainly attacking the human nervous system,long-term exposure to the environment H₂S will cause great harm to the human body,and even lead to death H₂S in the environment for a long time will cause great damage to the human body and even lead to death.Therefore,the detection of H₂S concentration becomes particularly important.SnO₂ is a classical n-type semiconductor and one of the most popular gas-sensitive materials in the field under study.Due to its relatively stable structure and properties,it has good response to light absorption,photocatalyst and sensitive reaction to gases,so it has been used as storage materials,gas sensors,photocatalyst materials and electrode materials etc.in recent years.Secondly,the morphology and structure of the material largely determine the gas-sensitive performance of the material,and the gas-sensitive properties of the material can be further enhanced by techniques such as doping with noble metals,constructing heterojunctions and modification.In this paper,SnO₂ is used as a sensitive material to design and prepare a gas sensor that can be used for H₂S detection.The controlled design of the modified SnO₂ material and the gas-sensitive performance to H₂S are explored in focus.The specific studies are as follows:Ag₃PO₄-doped SnO₂ materials,Sm₂Sn₂O₇-composite SnO₂ materials,and In₂O₃-composite SnO₂ materials with different morphologies were prepared by a solvothermal synthesis method combined with high-temperature treatment technology,and the morphology and structure of the products,as well as the gas-sensitive performance and response mechanism to H₂S,were investigated.The Ag₃PO₄-doped SnO₂ material consists of micron-sized rough spheres;the Sm₂Sn₂O₇-composite SnO₂ material consists of nanoscale particles stacked and adhered,and the In₂O₃-composite SnO₂ material consists of a layered structure of small nanoscale particles stacked.The three materials showed good gas-sensitive performance for H₂S at lower operating temperatures,including fast response,good linearity,high response values,and good selectivity.Overall,modified SnO₂ sensitive materials were prepared under hydrothermal synthesis method and calcination method.The modified SnO₂ gas sensors have potential applications for H₂S detection at lower operating temperatures.