綠色奈米技術之開發及應用－奈米金屬改質光觸媒於水中污染物及揮發性有機物控制之研究
| 中文摘要 | 本研究所製備的Ag/TiO2在中性溶劑中，可以維持懸浮，且容易附著在載體上，光反應效率高，具商業價值。以下為具體工業應用之貢獻：本研究開發的二氧化鈦鍍膜液，其二氧化鈦顆粒成紡綞形，不需添加界面活性劑，即可永遠保持懸浮，不會聚集，而且溶液為中性，不會對載體有侵蝕，並且不須再加熱處裡，即呈銳鈦型結構，將之鍍在載體表面，不須任何處理，附著性極高，不易剝落，具有極高的光催化活性。本研究將之加入銀後，其活性增加兩倍，不但在紫外光下有高活性，在太陽光下也有極高的活性，不但對廢水、廢氣處裡有高的效果，且有自潔與殺菌效果，在工業上已和廠商合作，有產品銷售。 本研究以製備各種新穎的光觸媒材料為主要目的，其中包括以溶膠凝膠法製備TiO2溶膠、添加奈米金屬之光觸媒以及一系列中孔型複合光觸媒。 以溶膠凝膠法所製備的TiO2溶膠係以四氯化鈦作為原料，經過水解、水洗、解膠及迴流加熱後，於中性範圍內，可得到透明的二氧化鈦奈米粒子懸浮溶液，其粒子的結晶型態為銳鈦礦。利用XRD、DLS、FTIR、TGA、DTA、DSC及TEM等儀器分析探討溶液的酸鹼值、過氧化氫添加量和加熱溫度時間的影響，以決定最佳的溶液組成及加熱條件；此時二氧化鈦大部分為紡綞狀的粒子，長軸約10 nm、短軸約4 nm。將此二氧化鈦粒子溶液以浸漬覆膜方式鍍於玻璃上，可得透明且牢固的光觸媒薄膜基材。經紫外光照射後之光觸媒玻璃基材一小時內，其接觸角會下降至0°以下。我們以亞甲基藍作為光催化降解的指標，由光催化反應結果可知，本研究製備的二氧化鈦溶膠覆膜於光觸媒玻璃基材上，對於亞甲基藍水溶液的光降解反應有不錯的轉化率，且容易附著於玻璃上，不易脫落。 添加奈米金屬之光觸媒，分別為Au/TiO2、Ag/TiO2、Cu/TiO2及Pt/TiO2。藉由光沉積法所製備的Au/TiO2其金顆粒約為1.5 nm，均勻分布在二氧化鈦擔體上，而不同的光源強度及照射的時間等製備條件的不同，會影響其金屬觸媒的顆粒大小，照光時間越長光源強度越強，皆會增加金顆粒的直徑，使用光沉積法所製備的Au/TiO2具有良好的光反應效率。而在Cu/TiO2的製備過程中，當銅負載量為1.5wt％時，對於紫外光催化有最佳的MB去除率。實驗結果證實含浸Cu確實能夠改進二氧化鈦在可見光源的催化效率。不同的金屬中，其活性為Pt/TiO2> Ag/TiO2> Au/TiO2> Cu/TiO2。 在中孔型複合光觸媒中，以NbCl5及In2O3為金屬前驅物，以有機共聚物P123為合成模版，已成功製備具有中型孔洞結構的In-Nb氧化物，當In含量增加時，In原子進入中孔型Nb2O5結構的量會跟隨著增加，孔徑變大及孔壁厚度變小。以溶膠凝膠法製備TiO2及TiO2-SBA-15光觸媒，將二氧化鈦擔載在SBA-15分子篩上，利用其高表面積及奈米孔洞之特性的中孔洞材料作為二氧化鈦光觸媒粉末擔體，以提高TiO2光觸媒於廢水處理的活性效率。將溶膠凝膠法製備TiO2及TiO2-SBA-15光觸媒於700℃下鍛燒可以得到結晶性較高的金紅石相TiO2，可提高亞甲基藍光降解反應活性。 本實驗所製備之奈米光觸媒，其種類可分為溶膠覆膜液、粉末及中孔性材料，溶膠覆膜液已可量產，將之鍍在載體表面，不須任何處理，附著性極高，不易剝落，具有極高的光催化活性。而添加奈米金屬之光觸媒活性大小之比較為Pt/TiO2> Ag/TiO2> Au/TiO2> Cu/TiO2。中孔性材料與二氧化鈦之合成材料其合成難度高，高吸附量為其優點，但其光催化活性並不佳。 | ||
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| 中文關鍵字 | 二氧化鈦溶膠光觸媒, 光觸媒薄膜基材, 金/二氧化鈦光觸媒, 銅/二氧化鈦光觸媒, 鉑/二氧化鈦光觸媒, 銦鈮氧化物光觸媒, SBA-15分子篩, 亞甲基藍, 光降解反應, 環保觸媒, 高親水性 | ||
基本資訊
| 專案計畫編號 | EPA-97-U1U1-02-102 | 經費年度 | 097 | 計畫經費 | 1860 千元 |
|---|---|---|---|---|---|
| 專案開始日期 | 2008/04/01 | 專案結束日期 | 2009/03/31 | 專案主持人 | 陳郁文 |
| 主辦單位 | 永續發展室(停用) | 承辦人 | 吳婉怡 | 執行單位 | 國立中央大學 |
成果下載
| 類型 | 檔名 | 檔案大小 | 說明 |
|---|---|---|---|
| 期末報告 | 環保署期末報告_定稿.pdf | 6MB | [期末報告]公開完整版 |
Study on the degradation of volatile organic pollutants in waste gas and water using metal modified nano-photocatalyst.
| 英文摘要 | The objective of this research was to develop a catalyst which is active in photoreaction to destruct organic compounds in waste gas and waste water. This study included using sol gel method to prepare TiO2 sol and adding various metals as the cocatalysts. Various mesoporous composite catalysts were also studied. The TiO2 sol was prepared by sol-gel method using TiCl4 as the starting material. TiCl4 was converted to Ti(OH)4 gel and H2O2 was used to hydrolyze Ti(OH)4 to form TiO2 sol The sol is stable in neutral condition and is in anatase structure. The particle size is in rhombus form and the long axis is 10 nm and short axis is 4 nm. It is well dispersed in water and does not agglomerate forever. TiO2 can be coated on the glass and become superhydrophilic. The contact angle of water on glass is 0o. It is also very active for destruction of methylene blue in water. Various metals, such as platinum, gold, silver and copper, were added on TiO2 as the cocatalysts. Au/TiO2 prepared by photodeposition had average Au particle size around 1.5 nm, which was homogeneously distributed on the surface of TiO2. The particle size of Au is a function of light source, power and irradiation time during preparation. Au/TiO2 prepared by deposition-precipitation had an Au particle size around 3 nm. Silver and copper catalysts were prepared by incipient-wetness impregnation to Degussa TiO2 and then reduced by UV light irradiation. Adding metals had significant improvement in destruction of methylene blue under UV light irradiation. It also had activity under visible light irradiation. The sunlight contains about 3% UV light. Therefore adding metal on TiO2 is very beneficial under sun light irradiation. The effect of cocatalyst was Pt> Ag> Au> Cu. The Ag/TiO2 sol prepared in this study was much more active than commercial Ag/TiO2. It is very stable in neutral condition and was very sticky on glass. It has been commercialized by some companies. In this study, we have invented the method to prepare Ag/TiO2 sol. It has commercial value. In this study, composite mesoporous materials were also synthesized. Mesoporous In-Nb oxides were synthesized using NbCl5 and In2O3 as the materials and P123 as the template. The higher the content of In, the bigger the pore size of materials and the thinner the pore wall. This materials has photoactivity. The high surface area of this material improved the photoactivity to some extent. TiO2-SBA-15 was also synthesized by sol-gel method. TiO2 was supported on the surface of SBA-15. These composite materials had high adsorption capacity to remove methylene blue due to the high surface area of SBA-15 and the activity was also quite high due to the syngertistic effect between TiO2 and SBA-15. | ||
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| 英文關鍵字 | TiO2 sol, Au/TiO2, Ag/TiO2, Cu/TiO2, SBA-15 mesoporous material, photocatalysis, methylene blue destruction, nanocatalyst, In-Nb oxide mesoporous material, superhydrohilicity | ||