【作者】 黄运瑞；

【导师】 周庆祥；

【作者基本信息】 河南师范大学 ， 环境科学， 2011， 博士

【摘要】 TiO2纳米管作为一种新型的二氧化钛材料,其主要在传感器、染料敏化太阳能电池、光电催化和光催化等领域有比较多的应用,在环境领域的应用主要是光电催化和光催化等方面。基于TiO2纳米管比TiO2纳米颗粒具有更大的比表面积,应具有更强的吸附能力。高度有序的TiO2纳米管阵列是近年来发展起来的一种TiO2新型材料,具有比TiO2纳米管颗粒更好的理化性质、更大的比表面积,TiO2纳米管与基底直接相连,结合非常牢固,不易脱落。TiO2纳米管阵列排列有序,不易团聚。为应用的稳定性及其回收利用奠定了比较好的基础,受到了国内外同行的广泛关注。但是它们在环境分析化学方面的应用非常少,基于其独特的理化性质,在环境领域理应发挥更大的作用,尤其是在环境污染物的高效富集与检测方面,应该具有更好的应用前景。本文在大量文献的基础上采用TiO2纳米管及其阵列开发了系列环境污染物的痕量分析检测方法,提出了微固相平衡萃取(μSPEE)技术,并初步研究了TiO2纳米管阵列对典型环境污染物的吸附机制。论文从总体上可分为四部分：第一部分综述了固相萃取与TiO2纳米管的研究进展。第二部分对TiO2纳米管作为萃取有机磷和苯甲酰脲杀虫剂的固相萃取吸附剂的可行性进行了探索。以毒死蜱、甲拌磷和甲基对硫磷作为研究对象,以正己烷作为洗脱剂,以气相色谱火焰光度检测作为分析手段,建立了以TiO2纳米管作为固相萃取剂检测环境水样中毒死蜱、甲拌磷和甲基对硫磷的灵敏方法。研究结果表明,TiO2纳米管可以实现对毒死蜱、甲拌磷和甲基对硫磷的高效富集,方法的检测限对毒死蜱、甲拌磷和甲基对硫磷分别为0.11、0.014、0.0025μg L-1,环境水样分析的加标回收率在86.5%-115.1%之间。TiO2纳米管对除虫脲、灭幼脲、杀铃脲、氟虫脲、氟啶脲等苯甲酰脲类杀虫剂也展现了优越的富集性能,与高效液相色谱联用建立的方法检测限在0.062-0.21μg L-1之间,对四种实际环境水样分析,加标回收率在82-100.2%之间。第三部分对TiO2纳米管阵列作为高效吸附剂的可行性进行了探索,提出了一种新型的萃取方式一微固相平衡萃取。以典型环境污染物联苯菊酯、甲氰菊酯、三氟氯氰菊酯、氰戊菊酯、溴氰菊酯等拟除虫菊酯类杀虫剂、六六六、DDT及其代谢产物、多氯联苯作为目标物,采用微固相平衡萃取考察了TiO2纳米管阵列的吸附性能,建立了相应的灵敏分析方法,并用实际水样进行了方法验证。研究结果表明,TiO2纳米管阵列对拟除虫菊酯类杀虫剂、六六六、DDT及其代谢产物、多氯联苯均具有很好的吸附性能,建立的方法对拟除虫菊酯类杀虫剂的检测限在0.018-0.070μgL-1,实际水样加标回收率在81.9-110.6%；六六六和DDT及其代谢产物的检测限在0.0076-0.10μg L-1,环境水样的加标回收率在78-102.8%；多氯联苯的检测限在0.02-0.10μg L-1,实际水样的加标回收率在95.8-110.5%。第四部分采用阳离子表面活性剂十六烷基三甲胺对TiO2纳米管阵列进行了修饰,研究发现用阳离子表面活性剂十六烷基三甲胺修饰过的TiO2纳米管阵列对多环芳烃有很强的吸附性能,多环芳烃能定量的被吸附在修饰过的TiO2纳米管阵列片上,实现高效富集。将微固相平衡萃取与高效液相色谱联用建立了多环芳烃的痕量分析方法,检测限在0.026-0.82μgL-1,实际环境水样的加标回收率在75.0-114%之间。以芘和荧蒽作为代表性物质,初步研究了它们的吸附等温线,对其在TiO2纳米管阵列上的吸附机制进行了初步探讨。更多还原

【Abstract】 Titanium dioxide nanotubes, a new type of TiO2 materials, have mainly used in many fields such as sensors, dye sensitized solar cells, photoelectric catalysis and photocatalysis, etc. They were widely used for photoelectric catalysis and photocatalysis in environmental field. They have larger specific surface area than that of titanium dioxide nanoparticles, titanium dioxide nanotubes should have much better adsorption ability. Recently, highly ordered TiO2 nanotube array was introduced as a new kind of TiO2 materials. In contrast, it has better physical and chemical properties, much larger specific surface area than that of TiO2 nanotube powders. Except these, TiO2 nanotube is connected with the substrate directly and tightly, and not easy to be desquamated. Because of the highly ordered structure and non-agglomeration, it is very easy to realize stable and cycled application of TiO2 nanotube array. So TiO2 nanotube array absorbed much more attention. However, there are very few reports on the application of TiO2 nanotube array in environmental analytical field. Due to their special physical and chemical properties, TiO2 nanotube array should play an important role in environmental field, especially in preconcentration and detection of environmental pollutants, and have a great prospect.In this thesis, a series of new analytical methods were developd to determine environment pollutants with TiO2 nanotubes and TiO2 nanotube array, and a novel enrichment technique micro-solid phase equilibrium extraction was well established. Further a preliminary study on the sorption mechanism was carried out. This thesis consists, of the following four parts:In the first part, the research progress of solid phase extraction and TiO2 nanotubes were reviewed.In the second part, the feasibility of TiO2 nanotubes as solid phase extraction absorbents for organophosphorus and benzoylurea pesticides was investigated. The experimental results showed that organophosphorus pesticides such as chlorpyrifos, phorate and methyl parathion could be quantitatively absorbed onto TiO2 nanotubes packed cartridge, and these compounds retained on the cartridge can be desorbed quantitatively with suitable amounts of n-hexane. The detection limits of the proposed method for the determination of chlorpyrifos, phorate and methyl parathion were 0.11,0.014,0.0025μgL-1 respectively. The analysis of real water samples demonstrated that satisfied spiked recoveries were achieved in the range of 86.5%-115.1%. The experimental results indicated that TiO2 nanotubes had good adsorption capacity for diflubenzuron, chlorbenzuron, triflumuron, flufenoxuron and chlorfluazuron in environmental water samples. A new, sensitive, and rapid method was developed for determination of such compounds with TiO2 nanotubes cartridge in combination with high performance liquid chromatography, and the detection limits were in the range of 0.0.62-0.21μgL-1. Four real water samples were used to validate the developed method, and the spiked recoveries were in the range of 82-100.2%.The potential of TiO2 nanotube array as absorbent for some organic pollutants was investigated in the third part. A new method micro-solid phase equilibrium extraction (μSPEE) procedure was established. The experimental results show that some organic pollutants such as pyrethroid pesticides, organochlorine pesticides and polychlorinated biphenyls can be quantitatively absorbed on TiO2 nanotube array sheet, then these compounds retained on the TiO2 nanotube array sheet can be desorbed quantitatively with little amounts of organic solvent, finally the analytes can be detennined by gas chromatography-electron capture detector. This method has been applied to determine pyrethroid pesticides, organochlorine pesticides and polychlorinated biphenyls in several environmental water samples. The detection limits of the developed method were 0.018-0.070μgL-1,0.10-0.0076μgL-1,0.020-0.10μgL-1 respectively. The spiked recoveries from real environmental water samples were in the range of 81.9-110.6%,78-102.8% and 95.8-110.5% respectively.In the last part, ordered TiO2 nanotube array which was modified with cetyltrimethylammonium bromide was used to preconcentrate polycyclic aromatic hydrocarbons (PAHs) based on micro-solid phase equilibrium extraction. The experimental results show that the modified ordered TiO2 nanotube array has good enrichment ability to PAHs. The detection limits of the developed method were in the range of 0.026-0.82μgL-1. The spiked recoveries from real environmental water samples were in the range of 75.0-114%. A primary study on the absorption mechanism was carried out with pyrene and fluoranthene as the model targets.更多还原