Preparation And Properties Of SnO₂ Multistage Structure And SnO₂ Composite Materials

With the development of science and technology research,materials at the nanoscale exhibit peculiar physical and chemical properties was further confirmed,the peculiar nature of nanomaterials has a broad application prospect.SnO2 is a kind of typical n-type broadband gap semiconductor material,its nanostructures has unique properties,such as optics,chemistry,electricity,and has very extensive application in the field of scientific research and industrial production.This paper prepared multilevel structure of SnO2 nanometer materials in the FTO substrate,and surface modification with Au nanoparticles as well as studied on its gas sensitive and light catalytic performance,the main research contents and results are as follows:(1)The relatively uniform urchin shaped SnO2(marked as SnO2-UCs)was prepared on the conductive glass FTO in acetic acid,ethanol and water through solvent hot method using SnCl4 · 5H2O as raw materials and NaBr as additives,multilevel structure not only let SnO2-UCs has a large specific surface area(74 m2/g),but also is beneficial to the collection and transport of electrons.The gas sensor of SnO2-UCs has good sensitivity and selectivity for CH3COCH3 gas,sensitivity of 100 ppm acetone gas reached 21 and is nearly 13 times than ordinary SnO2 powder.The photocatalyst of SnO2-UCs is 2.4 times than ordinary SnO2 powder on the degradation efficiency of Rhodamine B.(2)First,introducing a layer SnO2 crystal seed on the conductive glass FTO,the SnO2 flower-like three-dimensional structure(marked as SnO2-FLs)which using SnCl4· 5H2O and NaOH as raw materials was prepared without template agent and surfactant as well as under 200 ℃ through the hydrothermal method.Orderly flower-like branching structure possesses larger specific surface area(110 m2/g),active center and electronic channels and so on,which make it have better degradation activity.After two hours of UV irradiation,the degradation efficiency of Rhodamine B of the SnO2-FLs reached 91%.(3)The SnO2-UCs and the SnO2-FLs was modified with Au by immersion method.Gas sensitive performance test showed that sensitivity for 100 ppm acetone gas of ASUCs-10 and ASUCs-5 are 2.4 and 1.9 times than not load,ASFLs-10 and ASFL-5 are 1.9 and 1.5 times than not load,the improvement of the performance of the gas sensor is associated with the catalytic activity of Au nanoparticles.Photocatalytic performance,after two hours of UV irradiation,the degradation efficiency of Rhodamine B of the ASFLs-10 reached 100%.All the sample with loaded of the photocatalytic activity was improved and the absorbing peak in visible light region,the improvement of photocatalytic activity is derived from the surface plasmon resonance effect of Au nanoparticles.