【作者】 胡曰博；

【导师】 周大利； 何文；

【作者基本信息】 四川大学 ， 材料学， 2005， 硕士

【摘要】 国际纯粹和应用化学联合会(IUPAC)把孔径在2.0～50.0nm 的固体多孔材料定义为介孔材料(mesoporous materials)。介孔材料以其孔道大小均匀、有序排列且孔径连续可调、巨大的比表面积等独有的特点以及在催化、吸附、分离、纳米材料制备及光、电、磁等诸多领域潜在的应用价值,而迅速引起国际材料科学界的极大关注,成为新材料领域的一个研究热点。目前,以硅作为基体的介孔材料已取得了大量的研究成果,相关报道较多。非硅基介孔材料的研究开发相对滞后,但是此类材料在诸多领域存在着巨大的潜在应用价值,所以此类材料成为当前一个新的研究热点。TiO2因其特有的光催化活性、紫外光屏蔽效应等功能,以及化学性质稳定、毒性低、价格便宜和易于回收等特点,向来是广大科学研究人员关注的焦点,但到目前为止,对于介孔TiO2的研究,相关文献鲜见报道。溶胶-凝胶法(sol-gel)是湿化学方法中较为成熟的材料制备工艺,其特点是:设备简单,操作方便,易于控制;反应产物组成均匀,纯度高,易于后续处理等。吐温-80 (失水山梨醇油酸单酯聚氧乙烯醚) 和司班-80 (失水山梨醇油酸单酯) 是两种典型的非离子型表面活性剂,具有较好的乳化、分散、渗透和增溶等特性。吐温-80 的HLB 值为15,司班-80 的HLB 值为4.3,将两种表面活性剂合理搭配使用,可以达到所要求的HLB 值,改变其亲水特性。本研究首次在介孔TiO2制备体系中采用价廉易得及性能优良的表面活性剂吐温-80和司班-80更多还原

【Abstract】 Mesoporous materials defined by the International Union of Pure and Applied Chemistry (IUPAC) are a kind of solid porous materials whose apertures lie at 2.0～50.0nm. Mesoporous materials rapidly arose the broad attention in the international material science kingdom and become a investigate hotspot in new material domain, because they have the particular characteristic such as the size symmetrical aperture, the ordered arrange and the continuous regulablity of aperture, the huge surface area and the potential appliance values in the catalyze, adsorption, separation, nano materials’preparation and light, electricity, magnetism demain etc. At present, there are large numbers of research productions and reports on the mesoporous silicic materials. The investigation of non-silicic mesoporous materials are relatively lagged, but this kind of mesostructured materials are expected to show potential values in many application fields such as photocatalysis,electricity,magnetism. This non-silicic mesoporous materials become a new investigate hotspot at present. TiO2 is the study pivot for the scientific researchers always, because it has a lot of peculiarities,for instance the peculiar photocatalyse activity, shield function to ultraviolet radiation, chemical character stable, low-toxicity, low-cost and easy-reclaim. But up to now there are few reports on mesoporous TiO2 materials. Sol-gel method is one of the riper synthesis technology in waterish chemical methods. It’s characteristics are the simple equipment, the convenient manipulation, the easy controlling, the reaction outcome composition uniformity and purity of the outcomes higher, being apt to deal at next. Tween-80 and Span-80 that they have better peculiarity of emulsification, disperse, penetrate, increasing solubility are two kind of non-ion surfactant activator. The HLB of Tween-80 is 15 and the HLB of Span-80 is 4.3 and the want HLB may be acquired by mixing them, and their peculiarity of hydrophilic can be changed. This study used the inexpensive and easy to obtain Tween-80 and Span-80 as composite surfactant template and used TBOT as the raw material synthesized the ordered mesoporous TiO2 through sol-gel method. The micro-morphology and crystalline structure of the ordered mesoporous TiO2 were characterized by TEM, ESEM, HREM and XRD. The influence of pH value on gelation time and the effect of different depressors and heat-treating temperature on the structure were investigated. Results indicate: the hydrolyzation of TBOT is well restrained and the process of gelation is prolonged to about 8h when HNO3 is depressor and pH value at 4. After calcined under 500℃for 5h, the ordered mesoporous TiO2 was prepared. The sole particular of the outcomes observed by the HREM has the periodicity tactic and ordered hexagonal column mesoporouses at molecule size (the size of pore at 2～4nm). The thickness of pore wall is 2～3nm . The room structure observed by the SEM is better; The ordered mesoporous TiO2 validated by the design of XRD is anatase. After calcined under 600℃for 5h, the mesoporous morphological structure collapsed, dense laminar structure was obtained, the crystalline structure consisted of equal accout anatase TiO2 and rutile TiO2. The paper analyzes the outcomes’activity by photo-decomposing the methyl orange solution. The effects of the initial concentration of methyl orange solution, the illumination distance and the surfactant on the activity of mesoporous TiO2 had been studied. After used many times, the catalyst will lose its activity.In this study the catalyst was recovered by calcining again or rinsing method in the present study.The photodecompose ratio of the outcomes is higher than the selled TiO2 powder. In addition, this paper summarizes the application development foreground and questions in the study of mesoporous TiO2 materials. This paper puts forward advice to the next investigation in mesoporous TiO2 materials.更多还原