Preparation And Application Of Tungsten Oxide Nanoflower Material

The metal oxide nano materials were paid close attention to the researchers by the new physical properties in photo-electronics,sensors and photo-catalysis.In recent years,tungsten oxide nano materials,which is the transition metal oxides nano materials,become a focus in the field of science and engineering.Due to the special nano meter morphology and band structure,it obtained the great potential application value in the field of photoelectric device and electrochemical.In this paper,the research is focused on the compound preparation and application of three-dimensional tungsten oxide nano structure materials,respectively.We try different ways to prepared different tungsten oxide nano structure materials and applied in the field of gas sensor and photo-degradation of dye.And then,we research the materials by the characterization,performance test and theoretical analysis.It gives the main study tasks and contributions of this thesis as follows:1.The synthetic method of the metal oxides core shell nanoflowers?called seed planting method?was be developed and applied to grow the W-W₁₈O₄₉ core shell nanoflowers with a high specific surface area and a localized growth property.The material characterization technologies?SEM,XRD,TEM?and the record of the process in growth have proved the growth mechanism of the tungsten oxide nanoflowers.It will provide a new direction for accurate orientalist alignment and construction of artificial assemblies new three-dimensional composite nano materials.2.A WO₃ nanoflowers film with a high specific surface area was prepared in this chapter.Then the Pt were uniformly dispersed on the surfaces of the nanoflowers to form the Pt coated WO₃ nanoflowers film.To test the sensing property of the H2 gas sensor based on Pt coated WO₃ nanoflower film,and its gas sensing reaction mode was discussed.The experimental result indicated that the H2 gas sensor was able to detect the H2 concentration in air down to 50 and up to 5000 ppm at relative low temperature?25?,and the lower limit of detection range can satisfy the standards of ?industrial production.These features can also effectively compensate the deficiency of conventional semiconductor gas sensors and avoid the security risks during the process of use.3.Through high-temperature annealing and thermal oxidation of W metal,the W₁₈O₄₉ materials with oxygen defects was prepared on the carbon fiber.And the materials can degraded methyl orange dye in both the visible light and dark environment.Through the performance test of catalysis and analysis,we try to explore the oxygen defect W₁₈O₄₉ materials catalytic reaction mechanism of degradation of methyl orange.The significance of the study is that extends the tungsten oxide range of spectral response to visible light photo-catalytic materials area,thus it helps in the dark environment degradation of toxic dye molecules of water.