Preparation Of Dysprosium Trioxide Microspheres And Research On Humidity Sensitive Properties

It is necessary to real-time monitor and precisely control environmental humidity in the medical,food,industrial production,and scientific research fields.In addition,it is very important for people to accurately measure and maintain the relative humidity in the atmosphere for humans health and comfortable life.In this thesis,Dy₂O₃microsphere,Dy₂O₃ tube–globular and KCl/Dy₂O₃ tube–globular were prepared by solvothermal method.The Dy₂O₃ nanostructures were characterized by X-ray diffraction?XRD?,scanning electron microscope?SEM?,transmission electron microscope?TEM?,specific surface area test?BET?,and X-ray photoelectron spectroscopy?XPS?techniques.?1?The spherical Dy₂O₃ precursor was prepared by one-step solvothermal method using dysprosium acetylacetonate as the dysprosium source,isopropanol and methanol as solvent.The spherical Dy₂O₃ nanomaterial was obtained after sintering at 600^oC,The diameter of the Dy₂O₃ microsphere is about 800 nm?900 nm.Dy₂O₃ microsphere humidity sensor is sensitive in the range of 11.3?93.58%RH,the response time is within 2 s,the recovery time is 70 s and the humidity hysteresis is 1.5%RH.?2?The Dy₂O₃ tube–globular precursor was prepared for the first time by a convenient one-step solvothermal method using dysprosium acetylacetonate as the dysprosium source,ethylene glycol,polyethylene glycol-400 and deionized water as solvent.After sintering at 500^oC,Dy₂O₃ tube–globular nanomaterial was obtained.The Dy₂O₃ tube–globular nanostructure??900 nm diameter?was self–assembled by a large number of nanotubes with a diameter of about 20 nm.The growth mechanism of the tube–globular was studied at different times and temperatures.The Dy₂O₃ tube–globular humidity sensor has ultra-fast response speed?0.35 s?and ultra-low humidity hysteresis?0.96%?at 11.3?93.58%RH.?3?KCl/Dy₂O₃ composite material was prepared by KCl surface modification.The material showed excellent humidity sensitivity performance test.The response value is4 times higher than that of pure Dy₂O₃,and the humidity hysteresis is?0.33%?.And made a simple breath monitoring device to simulate a variety of conditions for testing.