Study On Preparation Of Two Nanocomposites Using Tin Oxide As Precursor And Their Photothermal Catalytic Performance

All normal lives of people on the earth depend on our ecosystem.Nowadays,people’s lives are progressing,transportation is convenient,and science and technology are advanced.Things that were once unimaginable have become reality.People living in the moment are lucky,but while enjoying this fortune,we must bear the responsibility for what will follow.Responsibility.The current environmental situation is really worrying.It is no longer a state where it can be developed.The shortage of non-renewable energy and the increase in the content of pollutants in the air are threatening our beautiful home.Fortunately,science and technology are advancing.At present,materials that degrade pollutants have been gradually developed.This material is a photothermal catalyst that has gradually entered people’s field of vision.A large number of studies have shown that photothermal catalytic technology can be used for environmental treatment without secondary pollution.Tin oxide（SnO₂）has the advantages of simple production process,low melting point,strong light absorption,good thermal conductivity,and low cost.It is a high-performance photocatalytic material with broad application prospects.However,the original SnO₂exhibits extremely poor ability to degrade pollutants.The reason is its weak ability to transfer electrons.Therefore,improving the catalytic performance of SnO₂is a hot research topic at present.In this thesis,SnO₂is used as the main body to prepare two kinds of catalytic materials.1.This article uses hydrothermal method to prepare SnO₂composite cobalt tetroxide（Co₃O₄）thermocatalytic material.During the preparation process,the quality of Co₃O₄is adjusted so that the molar ratio of SnO₂to Co₃O₄is 1:1,2:1,3:1respectively.Through the characterization and analysis of different samples,it is concluded that when the ratio is 1:1,the composite material has a larger specific surface area and a richer pore structure.According to the thermocatalytic performance test,it is concluded that the addition of Co₃O₄successfully reduces the thermal catalysis of SnO₂The starting temperature is higher,and the thermal catalytic activity is significantly improved.It is reasonable to believe that the increase in the specific surface area will increase the number of active sites and therefore the thermal catalytic performance.2.In this paper,the annealing method is used to prepare SnO₂composite chromium trioxide（Cr₂O₃）photocatalytic material.The calcination temperature is adjusted during the preparation process.Through the characterization and analysis of different samples,it is concluded that the band gap of the composite material becomes narrower and the absorption range of visible light becomes larger.The photocatalytic performance test and mechanism analysis of different samples show that when the annealing temperature is 500℃,the photocatalytic activity is the best,which benefits from the formation of PN-type heterojunction and the separation of photogenerated electron-holes.