【摘要】：納米二氧化鈦無毒,可以重復(fù)利用,而且光催化作用進(jìn)行的徹底,沒有二次污染。甲醛是一種被廣泛使用的工業(yè)原料,隨著它越來越多的使用,甲醛造成的空氣污染也越來越嚴(yán)重。用納米二氧化鈦凈化空氣中的甲醛是一種非常有前景的方法。但是,一些問題制約著二氧化鈦在治理甲醛污染方面的應(yīng)用。例如納米二氧化鈦光催化活性低、光響應(yīng)范圍窄、光催化過程受反應(yīng)條件影響顯著等。本文主要針對(duì)這些問題進(jìn)行了研究。采用溶膠-凝膠法制備了納米二氧化鈦光催化劑。用二浸二軋的方法制備了棉織物負(fù)載納米二氧化鈦復(fù)合光催化材料(以下簡(jiǎn)稱Ti02/CT)。用單因素變量法考察了鈦酸丁酯用量、乙醇用量、解膠時(shí)間以及解膠溫度四個(gè)制備條件對(duì)TiO_2/CT的光催化性能的影響。以主波長(zhǎng)為254nm的紫外燈為光源,以亞甲基藍(lán)為目標(biāo)降解物進(jìn)行測(cè)試。實(shí)驗(yàn)發(fā)現(xiàn)納米二氧化鈦的最佳制備工藝為：鈦酸丁酯體積分?jǐn)?shù)=9.1%,V(乙醇)：V(鈦酸丁酯)=0.5,解膠時(shí)間120min,解膠溫度60℃。分別制備了銀和鐵摻雜改性的納米二氧化鈦,用浸漬-煅燒的方法分別制備了玻璃纖維負(fù)載銀摻雜納米二氧化鈦(以下簡(jiǎn)稱Ag-TiO_2/GF)和玻璃纖維負(fù)載鐵摻雜納米二氧化鈦(以下簡(jiǎn)稱Fe-TiO_2/GF)。用掃描電鏡(SEM)觀察了負(fù)載前后玻璃纖維織物表面形態(tài)的變化；用紫外可見漫反射光譜測(cè)試考察了復(fù)合光催化材料的光譜吸收性能。以可見光高壓汞燈為光源,以甲醛為目標(biāo)降解物,考察了復(fù)合光催化材料的光催化性能。實(shí)驗(yàn)發(fā)現(xiàn),負(fù)載前后玻璃纖維表面發(fā)生了顯著的變化。不同比例的銀和鐵的加入使得催化材料的光譜吸收性能形成較大差異,金屬元素的摻雜量越大,催化材料對(duì)可見光的吸收能力越強(qiáng)。銀和鐵的加入均能使催化材料在可見光下對(duì)甲醛的凈化能力增強(qiáng),但這些元素的摻雜量不是越多越好。其中銀的最佳摻雜量是1.5%,鐵的最佳摻雜量是1%。研究了甲醛初始濃度、光照強(qiáng)度、催化劑負(fù)載層數(shù)三個(gè)因素對(duì)光催化材料可見光催化凈化甲醛效果的影響。實(shí)驗(yàn)發(fā)現(xiàn),隨著甲醛初始濃度提高,甲醛凈化率先變大再變小。甲醛初始濃度為941.tg/L時(shí),催化材料的凈化效果最好。隨著光照強(qiáng)度的加大,甲醛氣體的凈化率逐漸增加。反應(yīng)容器與光源的距離分別為20cm和80cm時(shí),凈化效果相差將近40%。負(fù)載層數(shù)為二時(shí),催化材料凈化甲醛的性能最好。
[Abstract]:Nano-TIO _ 2 is non-toxic, can be reused, and photocatalysis is carried out thoroughly, no secondary pollution. Formaldehyde is a widely used industrial raw material. With the increasing use of formaldehyde, the air pollution caused by formaldehyde is becoming more and more serious. Using nanometer titanium dioxide to purify formaldehyde in air is a promising method. However, some problems restrict the application of titanium dioxide in the treatment of formaldehyde pollution. For example, the photocatalytic activity of nano-TIO _ 2 is low, the range of light response is narrow, and the photocatalytic process is significantly affected by reaction conditions. This paper mainly focuses on these problems. Nano-TIO _ 2 photocatalyst was prepared by sol-gel method. Nano-TIO _ 2 composite photocatalytic material (Ti02/CT) supported on cotton fabric was prepared by two-dipping and two-rolling process. The effects of four preparation conditions, such as the amount of butyl titanate, the amount of ethanol, the time of degumming and the temperature of desorption, on the photocatalytic activity of TiO_2/CT were investigated by single factor variable method. UV lamp with the main wavelength of 254nm was used as the light source and methylene blue as the target for degradation. It was found that the best preparation technology of nano-TIO _ 2 was as follows: volume fraction of butyl titanate = 9.1%, V (ethanol -): V (titanate) = 0.5, degumming time 120 min, degumming temperature 60 鈩，

本文編號(hào)：2442107