The Solvothermal Synthesis Of Nano Tungsten Oxide (W₁₈O₄₉) And Performance Study

Tungsten oxide has some unique photochromic, gasochromic, photocatalytic properties, including W18O49 which is known to exist only in the pure state of non-stoichiometric tungsten oxide. There are a lot of oxygen defects in its crystal structure, making it have some unique features such as photochromic, near infrared absorption. But the research on the preparation of non-stoichiometric tungsten oxide(WO3-X), especially W18O49, is still under exploration. The already known preparation methods of tungsten oxide(WO3-X) require strict conditions for reaction, such as the synthetic difficulty, high cost and poor product controllability. So it is quite important to explore a new synthesis method of tungsten oxide(WO3-X) with low cost, simple operation, excellent morphologies.In present study, a series of tungsten oxide(WO3-X) nanoparticles, mainly W18O49, have been successfully synthesized with solvothermal method by changing the type of precursor solvent, the reaction temperature, time, as well as molar solution. The phase and morphology of the product have been characterized and the results showed: For using an alcohol solvent of n-propanol, when the reaction temperature reaches 200 ℃, time 24 h, solution molar concentration 15 m M, the phase and morphology of the product are the best; For using alcohol solvent of isopropanol, when the reaction temperature is 180 ℃, time 12 h, solution molar concentration 25 m M, the phase and morphology of the product are the best; For using alcohol solvent of ethanol, the reaction temperature is 180 ℃, time 24 h, solution molar concentration 15 m M, the phase and morphology of the product are best The performance research is focused on the Rh B adsorption and UV–visible-near infrared absorption. The results showed that using an alcohol solvent of isopropanol, the reaction temperature 180 ℃, time 12 h, solution molar concentration 25 m M, the obtained tungsten oxide(WO3-X) has the best adsorption properties. All the tungsten oxide(WO3-X) nanoparticles have good near-infrared absorption properties.In conclusion, the synthesis methods of tungsten oxide(WO3-X) with low cost, simple operation, excellent morphologies and properties are discussed. At the same time, the effect of different reaction conditions on the phase constitution and morphology of the prepared oxidized tungsten(WO3-X) nanoparticles is elucidated. The formation and growth mechanism has been preliminarily explored. The products feature the good Rh B adsorption and near-infrared absorption. Meanwhile, the results of BET tests of the prepared tungsten oxide(WO3-X) powder prove that the nanoparticles have a large surface area and a relatively uniform pore size distribution.