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    Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/3877


    Title: 二氧化鈦的合成與光催化性質的研究
    Authors: 葉世墉;Shih-Yung Yeh
    Contributors: 化學工程與材料工程研究所
    Keywords: 二氧化鈦;光催化反應
    Date: 2005-06-21
    Issue Date: 2009-09-21 12:24:54 (UTC+8)
    Publisher: 國立中央大學圖書館
    Abstract: 摘要 二氧化鈦是一種具半導體性質的觸媒,可利用紫外光的照射進行有機污染物的光催化分解反應。本研究主要分成兩部分,一部分是利用改良式溶膠凝膠法合成二氧化鈦光觸媒,所使用的前驅物為四丁基醇氧鈦以進行水解、縮合反應。並利用不同合成的程序以及煅燒溫度來達到控制二氧化鈦粒徑大小、結晶型態及結晶度,並以波長為350 nm的光源進行水楊酸的光催化分解反應測試。另一部分為了減小二氧化鈦能隙,改變二氧化鈦光吸收特性以利用可見光,嘗試合成出具有可見光光催化活性的二氧化鈦光觸媒。採取兩種方式,其一為在溶膠凝膠法合成二氧化鈦的水解反應中添加Cr3+、Fe3+與V4+等過渡金屬離子;另一種方式是在二氧化鈦裡摻雜氮。以波長470 nm的LED光源進行水楊酸的光催化分解反應測試。 在第一部分可以發現在同一個程序中,當煅燒溫度越高、結晶度越好而結晶型態還維持在anatase時,其紫外光催化反應速率有增加的趨勢,隨著煅燒溫度升高,結晶型態有rutile出現反應速率則開始下降,rutile比例越高,反應性越差;不同程序中,兩者雖然都煅燒到200℃,表面積相差不多,但是有較好結晶度的二氧化鈦其反應速率也較高。第二部分中,添加Fe3+與Cr3+的二氧化鈦在200 ℃溫度煅燒下,可見光光催化反應活性遠比添加V4+的二氧化鈦要好,且該三種二氧化鈦的光催化活性皆比P-25在可見光範圍要高。另外,添加氮的二氧化鈦,則是利用氨氣對TAYCA公司光觸媒AMT-100在400 ℃熱處理比用硫酸鈦加氨水沉澱合成的二氧化鈦可見光催化效果好。不管是過渡金屬還是氮,過量摻入皆會破壞二氧化鈦的結構形成缺陷,該缺陷會成為電子電洞再結合中心,導致反應活性下降。 Abstract Titanium oxide is a semi-conducting photocatalyst. It can decompose the organic pollutants by irradiation under UV light. This study is divided into chiefly two parts: the first part is the syntheses of TiO2 by modified sol-gel method using titanium n-butoxide as Ti-precursor. Different synthetic procedures and calcination temperatures lead to different crystallinity, crystal sizes and crystal forms of TiO2. Photo-decomposition of salicylic acid under irradiation of UV light (350 nm) was studied. In the second part, visible light active photocatalysts were prepared by incorporation of transition metal ions (Cr3+, Fe3+ and V4+) and doping nitrogen. Photo-decomposition of salicylic acid under irradiation of visible light (470 nm) was studied. High UV light photocatalytic activities were obtained with catalysts of highly crystalline anatase phase after calcinations at high temperature. But the activities decrease when mixing phases of anatase and rutile are obtained. The photo-decomposition activity of Cr3+ and Fe3+ modified TiO2 are higher than V4+ modified TiO2. The photo-decomposition activity of transition metal ions modified TiO2 are all higher than P-25 in visible region. The photo-decomposition activity of TiO2 (AMT-100) after heat treatment under ammonia atmosphere at 400 ℃ is the best. Either transition metal ions incorporation or nitrogen doped TiO2 cause defects in TiO2 crystal. The electron-hole recombination at defect sites induces decay of photo-decomposition activity.
    Appears in Collections:[化學工程與材料工程研究所] 博碩士論文

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