【作者】 刘丹；

【导师】 李祥村； 贺高红；

【作者基本信息】 大连理工大学 ， 化学工程， 2014， 硕士

【摘要】 TiO2多孔材料由于比表面积大、活性位多、无毒、氧化能力强、稳定性好、光催化活性高等性能在有机污染物的吸附、降解领域广泛应用。但指状孔的TiO2多孔材料结构不稳定,且TiO2是高能带半导体(3.2eV),只能吸收紫外光(<400nm),而紫外光只占太阳光的5%,故TiO2对太阳光的利用率低,因此需要通过改性来提高TiO2对可见光的利用率和性能。本论文主要利用-SO3H和Au对TiO2多孔材料进行改性,提高了其吸附性能和光催化性能。以四异丙基钛酸酯(TIP)和正硅酸乙酯(TEOS)为前驱体,采用表面活性剂自组装软模板法将SiO2掺杂到TiO2中,成功制备了SiO2-TiO2复合材料。红外光谱分析(FTIR)表明：SiO2-TiO2复合材料中存在Ti-O-Ti、 Si-O-Si和Ti-O-Si三种化学键。将制备的复合材料进一步-SO3H功能化(SiO2-TiO2-SO3H),以水溶液中的碱性品红为目标污染物,考察了改性材料对染料的吸附性能,红外谱图结果显示,经-SO3H功能化的材料,表面负载大量-SO3H基团,电负性较高,对阳离子染料具有较优的吸附性能,通过静电作用吸附溶液中的碱性品红,吸附率达90%以上。通过吸附动力学研究发现,染料的吸附动力学能很好的符合伪二级动力学模型,经线性拟合得到的相关系数R2均大于0.996。针对TiO2多孔材料对太阳光利用率低的问题,采用柠檬酸钠还原法制备了担载Au的TiO2多孔复合材料,电镜照片显示TiO2指状孔结构没有被Au颗粒堵住,仍能保持指状孔结构的完整性,Au成功沉积到了TiO2多孔材料的表面和孔道内,其中样品多孔TiO2-Au-500℃-l:16复合材料中Au的重量百分比和原子百分比分别为1.54%和0.16%。在可见光和紫外光照射下,TiO2-Au-500℃-1:16复合多孔材料的光催化活性均达到最高,紫外光下对甲基蓝的降解亚率为86.13%,可见光为49.74%。ln(C0/Ct)与t呈现出很好的线性关系,TiO2-Au多孔复合材料降解反应属于一级动力学反应,遵从Langmuir-Hinshelwood光催化动力学模型。为进一步提高多孔TiO2材料对碱性染料的吸附和降解性能,制备了经Au和-SO3H双重改性的多孔TiO2复合材料,即TiO2-Au-SH/SO3H。电镜和EDX测试显示多孔TiO2-Au-SH/SO3H复合材料的各元素在该材料的表面均匀分布、孔道结构高度有序、排列整齐。多孔TiO2-Au-SH复合材料对Ag+、Pb2+均有很好的吸附性能,吸附率分别为91.13%和99.80%。多孔TiO2-Au-SO3H复合材料对亚甲基蓝去除率,在紫外光下达87.89%,可见光下为80.22%,吸附效率为52.97%。更多还原

【Abstract】 More and more researchers are making their efforts to study on the TiO2porous materials for its significant properties. But TiO2porous material with the holes’structure more like finger, is unstable, and TiO2can be only absorb ultraviolet light, which is only a small part of sunlight. Hence, the adsorption capacity for visible light of TiO2materials should have still to be improved. In this thesis, the research is primarily on the modification of TiO2porous materials and characterization of the modified TiO2porous materials.SiO2-TiO2porous composite materials were successfully synthesized based on the surfactant self-assembly technology, with tetrabutyl titanate (TIP) and tetraethyl orthosilicate (TEOS) as precursors. The material structures were characterized by XRD, FESEM and FTIR. The results demonstrate that the Ti-O-Ti、 Si-O-Si and Ti-O-Si bonds are formed in the SiO2-TiO2composites. The composite materials was further functionalized by sulfonic acid, and the adsorption performance of-SO3H functionalization materials were evaluated by dye adsorption in aqueous solution. The results indicate that-SO3H modified materials have a large adsorption capacity to basic fuchsin, and the adsorption rate can reach as high as90%. The reason of large adsorption capacity can be attributed to the strong electrostatic interactions between basic fuchsin and the-SO3H groups. The dye adsorption kinetics follows the pseudo second-order kinetic model,and the correlation coefficient R2are greater than0.996.The metal Au was deposited on the surface of the patterned porous TiO2by sodium citrate reduction method, these porous composite materials were designated as TiO2-Au. The channel of porous TiO2-Au composite materials was not blocked by Au and finger channel pore structure was still maintained and arranged in parallel. The SEM micrographs of nanocomposites TiO2-Au indicated that metal Au was successfully deposited on the TiO2, the Au weight percentage and atomic percentage of TiO2-Au-500℃-l:16was1.54%and0.16%. The photocatalytic activity of porous composite materials TiO2-Au-500℃-l:16is the best under both the visible light and UV light. The porous composite materials degradation of methylene blue by the porous composite materials reached86.13%under UV-light and reached49.74%under visible light. Ln(Co/Ct) and t showed a good linear relationship. The photocatalytic process of porous composite materials was fited for pseudo-first-order kinetics, according Langmuir-Hinshelwood photocatalytic kinetic model.Based on the experiment of results and the experiment content of the first and second chapters, the porous TiO2materials modified by Au and-SO3H was prepared. The elements of TiO2-Au-SH/SO3H are uniformly distributed in the composite material surface and channel. The finger channel of the composite materials was still maintained and arranged in parallel. The band edge of TiO2-Au-SO3H was540nm. The TiO2-Au-SH composites materials have good adsorption properties for Ag+and Pb2+, and the dsorption rate are91.13%and99.80%. The removal of methylene blue by the composite porous materials TiO2-Au-SO3H is better than others, which reaches87.89%under UV light and80.22%under visible light, and the adsorption is52.97%.更多还原