Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/5303
標題: 以化學氣相沈積法製備二氧化鈦光觸媒之研究
The Study of Photocatalyst with TiO2 Preparing by CVD Method
作者: 吳怡玲
Wu, Yi-Ling
關鍵字: Taguchi Method;田口式實驗計畫法;TiO2 Photocatalyst;Chemical Vapor Deposition (CVD);Toluene;二氧化鈦光觸媒;化學氣相沈積法;甲苯
出版社: 環境工程學系
摘要: 
摘 要
本研究係以田口式實驗計畫法進行CVD製備二氧化鈦薄膜之探討,以期得到較佳光催化分解效果之光活性觸媒。
研究第一階段依據田口式直交表實驗計畫對製備參數進行多因素實驗分析探討,藉以尋求光觸媒製備之最佳組合及顯著影響因素。實驗結果顯示,最佳組合條件為水浴溫度85℃、Ti(OC3H7)4/H2O Ratio=4、載流氣體流速550 ml/min.、氧化溫度400℃、氧化時間10 hrs、鍛燒溫度500 ℃、高溫爐旋轉速度20 rpm、高溫爐直線運動減速馬達速度75 cm/min.,且其推定值有效範圍為85.53±16.18%;另外,由貢獻率結果顯示,顯著影響因素為氧化溫度及鍛燒溫度,可見在製備二氧化鈦之光觸媒反應中,此二項控制因素之改變將對製備之光觸媒產生較明顯之影響。
第二階段針對貢獻率較大之控制因素-氧化溫度及鍛燒溫度二項進行單因素實驗分析。綜合單因素實驗結果,顯示氧化溫度為400℃、鍛燒溫度500℃製備之觸媒具較佳之光催化能力。由表面顯微結構顯示,此觸媒呈米粒圓錐狀,觸媒表面具相當體積之微孔隙,表面積大;由表面晶型顯示,呈Anatase相結晶,繞射峰波峰強度強,結晶度高。另外,以此觸媒進行56.56 ppmv甲苯之光催化分解實驗,顯示其轉化率可高達0.998,且觸媒活性能維持16分鐘,於第16分鐘之後始產生觸媒衰退現象。再以此最佳製備條件探討光觸媒於衰退後觸媒活性能夠100﹪回復之活化時間,結果顯示於120分鐘內、水氣存在之條件下照光活化,即可將觸媒之活性完全回復。
最後針對有無鍛燒測試進行實驗,於氧化溫度500℃製備之二氧化鈦觸媒雖不經後續之500℃鍛燒程序,其做為觸媒之催化能力仍可與經過鍛燒處理者相當。但是,若考量觸媒回復率之容易度及薄膜附著力之強弱,未經鍛燒之觸媒由SEM表面結構發現其孔洞較小、觸媒附著力差,因而造成回復率差且有粉體剝落之虞,證實高溫鍛燒處理確實有其必要性。

ABSTRACT
This investigation aimed at preparing a titanium dioxide membrane by chemical vapor deposition (CVD) method, and finding the optimum preparation condition for the best photocatalytic efficiency by Taguchi method.
The experimental results indicated that the optimum operation parameters for preparing TiO2 photocatalyst were bath temperature = 85℃, Ti(OC3H7)4/H2O ratio = 4, carrier gas flow rate = 550 ml/min, oxidation temperature = 400℃, oxidation time = 10 hours, calcination temperature = 500℃, rotating speed of reactor = 20 rpm, linear velocity of reactor = 75 cm/min. Moreover, the significant parameters were oxidation temperature and calcination temperature for the photocatalytic efficiency of TiO2 according to the contribution ratio.
Based on the results of orthogonal array, this study proceeded the single parameter experiments for the significant affecting factors. The oxidation and calcination temperature of 400℃ and 500℃ showed the best photocatalytic activity. Furthermore, the TiO2 catalyst showed rice shape and anatase crystalline structure according to the analyses of SEM and XRD. Moreover, the conversion rate of 56.56 ppmv toluene was 0.998 for this catalyst, and the deactivity was occurred at 16 minutes. When the influent was toluene absent and under moisture condition, the photo-activity would be recovered within 120 minutes by irradiating UV light.
For the calcined necessity experiment, the non-calcined and calcined catalyst at oxidation temperature of 500℃ were the similar photocatalytic activity. However, the non- calcined catalyst had the worse recovery of deactivity catalyst and coating strength. It indicated that the calcination was necessary for TiO2 catalyst.
URI: http://hdl.handle.net/11455/5303
Appears in Collections:環境工程學系所

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