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URN etd-0905112-175033 Statistics This thesis had been viewed 1618 times. Download 362 times. Author Feng-Wen Zheng Author's Email Address No Public. Department Chemical Engineering Year 2011 Semester 2 Degree Master Type of Document Master's Thesis Language English Page Count 116 Title A Comparative Study of Different Methods to Prepare TiO2 for Photocatalytic Degradation of 2,4-dichlorophenoxyacetic Acid Keyword brookite anatase TiO2 photocatalytic photocatalytic TiO2 anatase brookite Abstract Four synthesic methods are used to prepare titanium oxide powder at different heat treatment temperatures. The chemical and physical properties of the photocatalyst samples were determined by X-ray diffraction (XRD), Scanning electron microscopy (SEM) and UV–vis diffuse reﬂectance spectra (UV-vis), also the specific surface area of all samples was measured by BET method.
The XRD results show that the TiO2 prepared by direct hydrolysis method and heat treatment at 85oC for 12 hrs in an oven has anatase and brookite phases. Brookite phase content and surface area are decreased with increasing that treatment temperature.
The photocatalytic activity performance of photocatalyst was evaluated by UV-vis spectrophotometer to detect the concentration of 2,4-dichlorophenoxyacetic acid (2,4-D). Hydrolysis-TiO2 prepared at heat treatment temperature of 85oC has higher photocatalytic activity performance than 25oC, 50oC, 200oC, 300oC and 400oC, as well as the other synthesic methods prepared at low temperature heat treatment. It can be attributed to that the synergistic effect of heterojunction in anatase/brookite composite can inhibit recombination rate of electrons and holes pairs to improve photodegradation performance.
Advisor Committee Rong-Chi Wang - advisor
Lii-Ping Leu - co-chair
Tai-Shang Chen - co-chair
Files Date of Defense 2012-07-26 Date of Submission 2012-09-06