金属有机骨架复合材料及衍生复合材料的研究

发布时间：2018-09-14 08:48

【摘要】：近年来,金属有机骨架(MOFs)材料以其出众的比表面积、高孔隙度、丰富的不饱和金属位点以及孔道可裁剪修饰等多样性被广泛应用于气体存储和分离、催化降解、药物缓释、光电材料等领域。很多新型MOFs材料和功能化MOFs材料被合成出来,此外,以MOFs为前躯体／模板,合成具有一定形貌的多孔金属氧化物也引起了广发关注,这些都大大扩展了MOFs在多个领域的应用。在本论文中,为了处理日趋严重的水污染环境问题,我们通过对MOFs进行磁性功能化修饰,合成出了一种便于回收的磁性MOFs来作为去除染料的吸附剂,并以MOFs为模板,合成多孔金属氧化物新型光催化复合材料来进一步处理污水,本论文的主要内容有如下三点：1.在常温下,我们通过一种简单高效的方法对MOFs进行功能化修饰,合成了一种磁性Fe3O4/ZIF-8纳米复合材料,所合成的磁性复合材料不但保留了MOFs的多孔性还具有良好的磁学性质,在外加磁场作用下可以很好的进行磁性分离,并可以通过控制Fe304纳米粒子的含量来改变复合材料的磁性。实验发现,该复合材料对对苯二酚具有非常高的吸附能力,吸附动力学遵从准二级动力学模型,吸附等温线符合Langmuir等温吸附模型,且最大饱和吸附量达到了2527 mgg-1。该复合材料还具有良好的循环再生能力,在经过3次循环实验之后仍能保持90%以上的吸附能力,稳定的晶体结构和磁学性质,良好的分离效果和高效的吸附能力使其成为了一种具有竞争力的吸附剂候选材料。2.为了提高金属氧化物的稳定性和光催化活性,我们用吸附Ag+的MIL-88来作为模板,通过一步煅烧法合成了一种具有一定形貌的多孔Ag/α-Fe2O3复合材料,且与传统方法合成的材料相比具有较高的比表面积。用它作为光催化材料来考察其在可见光下催化降解罗丹明B的性能。研究发现,我们合成的Ag/α-Fe2O3复合材料的光催化性能随着固载Ag粒子的含量的增加而增加,Ag粒子与α-Fe2O3的协同作用提高了其催化效率。该复合材料具有良好的稳定性,经过五次循环实验之后仍能保持良好的催化效果和晶型结构,我们期望为今后以MOFs为模板合成不同形貌和尺寸金属和金属氧化物复合材料提供了一个方向。3.我们了为了合成具有特定性质和在可见光具有良好催化效果的半导体材料,我们以吸附Ag+的ZIF-8作为模板,通过两步煅烧法合成具有一定形貌的多孔Ag/ZnO半导体复合材料,我们考察了其在可见光下对次甲基蓝(MB)的催化降解能力。研究发现,复合材料的Ag粒子与ZnO在合适比例使催化效果达到最佳,与此同时,该复合材料具有较好的光催化稳定性,三次催化循环之后催化剂的催化效果和晶型都没有发生明显变化。
[Abstract]:In recent years, organometallic skeleton (MOFs) materials have been widely used in gas storage and separation, catalytic degradation and drug release due to their outstanding specific surface area, high porosity, abundant unsaturated metal sites and pore tailable modification. Optoelectronic materials and other fields. Many new MOFs materials and functionalized MOFs materials have been synthesized. In addition, the synthesis of porous metal oxides with certain morphologies using MOFs as precursor / template has attracted wide attention, which has greatly expanded the application of MOFs in many fields. In this paper, in order to deal with the increasingly serious environmental problem of water pollution, we synthesized a magnetic MOFs, which is easy to be recovered, as an adsorbent for dye removal by magnetic functionalization modification of MOFs, and used MOFs as a template. A new type of porous metal oxide photocatalytic composite was synthesized to further treat wastewater. The main contents of this thesis are as follows: 1: 1. At room temperature, a magnetic Fe3O4/ZIF-8 nanocomposite was synthesized by functionalizing MOFs by a simple and efficient method. The synthesized magnetic composite not only retains the porosity of MOFs, but also has good magnetic properties. Magnetic separation can be well carried out under the action of external magnetic field, and the magnetic properties of composites can be changed by controlling the content of Fe304 nanoparticles. It was found that the composite had a very high adsorption capacity for hydroquinone. The adsorption kinetics followed the quasi-second-order kinetic model, and the adsorption isotherm was in accordance with the Langmuir isotherm model, and the maximum saturated adsorption capacity reached 2527 mgg-1.. The composite also has good recycling and regeneration ability, and can maintain more than 90% adsorption ability, stable crystal structure and magnetic properties after three cycles. Because of its good separation effect and high adsorption ability, it has become a competitive candidate material for adsorbent. 2. In order to improve the stability and photocatalytic activity of metal oxides, a porous Ag/ 伪 -Fe _ 2O _ 3 composite with a certain morphology was synthesized by a one-step calcination method using MIL-88 adsorbed by Ag as a template. Compared with the traditional method, the material has a higher specific surface area. The catalytic degradation of Rhodamine B in visible light was investigated by using it as a photocatalytic material. It is found that the photocatalytic activity of the synthesized Ag/ 伪 -Fe _ 2O _ 3 composite increases with the increase of the content of Ag particles. The synergistic effect of Ag particles and 伪 -Fe _ 2O _ 3 increases the catalytic efficiency. The composite has good stability and can maintain good catalytic effect and crystal structure after five cycles. We hope to provide a direction for the synthesis of metal and metal oxide composites with different morphologies and sizes using MOFs as template in the future. In order to synthesize semiconductor materials with specific properties and good catalytic effect in visible light, porous Ag/ZnO semiconductor composites with certain morphology were synthesized by two-step calcination method using ZIF-8 adsorbed by Ag as template. The catalytic degradation of methylene blue (MB) in visible light was investigated. It was found that the Ag particle and ZnO of the composite had the best catalytic effect at the appropriate ratio, and the composite had good photocatalytic stability. The catalytic effect and crystal form of the catalyst did not change obviously after the third cycle.
【学位授予单位】：安徽大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ26;TB33

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