负载纳米二氧化钛织物在可见光下降解甲醛气体的研究
发布时间：2019-03-17 08:26
【摘要】：纳米二氧化钛无毒,可以重复利用,而且光催化作用进行的彻底,没有二次污染。甲醛是一种被广泛使用的工业原料,随着它越来越多的使用,甲醛造成的空气污染也越来越严重。用纳米二氧化钛净化空气中的甲醛是一种非常有前景的方法。但是,一些问题制约着二氧化钛在治理甲醛污染方面的应用。例如纳米二氧化钛光催化活性低、光响应范围窄、光催化过程受反应条件影响显著等。本文主要针对这些问题进行了研究。采用溶胶-凝胶法制备了纳米二氧化钛光催化剂。用二浸二轧的方法制备了棉织物负载纳米二氧化钛复合光催化材料(以下简称Ti02/CT)。用单因素变量法考察了钛酸丁酯用量、乙醇用量、解胶时间以及解胶温度四个制备条件对TiO_2/CT的光催化性能的影响。以主波长为254nm的紫外灯为光源,以亚甲基蓝为目标降解物进行测试。实验发现纳米二氧化钛的最佳制备工艺为：钛酸丁酯体积分数=9.1%,V(乙醇)：V(钛酸丁酯)=0.5,解胶时间120min,解胶温度60℃。分别制备了银和铁掺杂改性的纳米二氧化钛,用浸渍-煅烧的方法分别制备了玻璃纤维负载银掺杂纳米二氧化钛(以下简称Ag-TiO_2/GF)和玻璃纤维负载铁掺杂纳米二氧化钛(以下简称Fe-TiO_2/GF)。用扫描电镜(SEM)观察了负载前后玻璃纤维织物表面形态的变化；用紫外可见漫反射光谱测试考察了复合光催化材料的光谱吸收性能。以可见光高压汞灯为光源,以甲醛为目标降解物,考察了复合光催化材料的光催化性能。实验发现,负载前后玻璃纤维表面发生了显著的变化。不同比例的银和铁的加入使得催化材料的光谱吸收性能形成较大差异,金属元素的掺杂量越大,催化材料对可见光的吸收能力越强。银和铁的加入均能使催化材料在可见光下对甲醛的净化能力增强,但这些元素的掺杂量不是越多越好。其中银的最佳掺杂量是1.5%,铁的最佳掺杂量是1%。研究了甲醛初始浓度、光照强度、催化剂负载层数三个因素对光催化材料可见光催化净化甲醛效果的影响。实验发现,随着甲醛初始浓度提高,甲醛净化率先变大再变小。甲醛初始浓度为941.tg/L时,催化材料的净化效果最好。随着光照强度的加大,甲醛气体的净化率逐渐增加。反应容器与光源的距离分别为20cm和80cm时,净化效果相差将近40%。负载层数为二时,催化材料净化甲醛的性能最好。
[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，
本文编号：2442107
[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，
本文编号：2442107
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