| Summary: | 碩士 === 龍華科技大學 === 機械工程系碩士班 === 102 === Tungsten oxide possesses superior physicochemical properties with promising applications in photocatalysis, photochromism, electrochromism and sensors. In terms of its nanoscale, the properties of tungsten oxide are greatly influenced by its morphology, microstructure and composition. With a higher surface area, the sensitivity of the sensor and the photocatalytic activity will be much improved.In this study, tungsten oxide and sodium tungstate were adopted as precursor materials, and the microwave-assisted synthesis was used to produce the flower-like tungsten oxide powder. By changing the microwave time, the microwave power and the microwave temperature to enable the synthesis, observing the changes of its morphologies, the structure and the optical properties can be further analyzed. Successfully, the microwave-assisted synthesis has been adopted over the traditional hydrothermal method, reducing the processing time from dozens of hours to a few minutes or hours, along with a highly efficient synthesis achieved.The flower-like tungsten trioxide prepared in this study has a higher specific surface area resulting from its complex structure and morphology, which is beneficial for the application in the photocatalytic activity. The largest specific surface area measured from this study is thirteen times larger than the tungsten trioxide particle available in the market, and the absorbence is specifically stronger at the wavelength of 225 nm. The best preparation conditions are with the microwave temperature of 100℃, the power of 200W, the microwave time of 120 minutes, and the specific surface area of 105.31 m2∕g and a complete flower-like structure will be achieved.
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