磁性纳米复合材料的制备及其分析检测与催化应用的研究

发布时间：2018-05-11 10:13

本文选题：Fe_3O_4纳米磁球 + 金/银纳米颗粒　；参考：《华东师范大学》2017年硕士论文

【摘要】：近年来,有机污染物的催化降解和检测以及与健康相关物质的分析检测,引起了人们高度的关注。由于自然环境和人体环境具有复杂性和难修复性,故循环催化率高和催化活性可控催化剂的制备以及无损、快捷的检测方法的构建具有重要的现实意义。随着纳米科技的发展,磁性纳米材料对外磁场的磁响应性在以上问题的解决中具有重要的研究价值。本论文主要开展了基于负载金纳米球(gold nanoparticles,AuNPs)/银纳米球(silver nanoparticles,AgNPs)Fe3O4的磁性纳米复合材料的循环可控催化降解和表面增强拉曼散射(SERS)无损分析检测的应用研究。具体内容如下:(一)我们设计并制备了一类磁响应性纳米复合材料,通过对其进行XRD、SEM、TEM、磁滞回归线的表征证实两种尺寸类型(600nm和40nm)的磁性纳米复合材料的成功合成,金属纳米颗粒的负载效果良好,材料粒径分布均一,水中分散性好,磁饱和度高达59emug/g。(二)随后,我们基于磁性纳米材料的磁响应性和催化性,将其应用于NaBH4还原降解亚甲基蓝(MB)的反应中,考察了它的催化性能。在我们的实验中,Fe3O4-13 nm-AuNPs的催化性能是最优的,仅在5 min内对MB的催化降解率可达到92%。同时,在循环催化3轮降解反应中,该催化剂的催化性能和形貌几乎没有任何变化。此外,长期稳定性良好,以粉末形态保存6个月后,该催化剂的催化性能仍旧几乎无变化。(三)更进一步的,我们考察了所制备Fe3O4-30nm-AuNPs、Fe3O4-AuNIs和 Fe3O4-AgNPs 的表面增强拉曼光谱(SERS)性能,Fe3O4-AuNIs 和 Fe3O4-AgNPs的SERS性能优于Fe3O4-30 nm-AuNPs,说明基底的材料组分和形貌结构对其SERS有影响。然而,Fe3O4-AuNIs的制备较繁琐,Fe304-AgNPs中的Ag易被氧化,故在后续研究中,我们选用Fe3O4-30nm-AuNPs作为增强基底,在针对罗丹明6G(R6G)的SERS检测中,检测灵敏度可达10 nM。
[Abstract]:In recent years, the catalytic degradation and detection of organic pollutants and the analysis and detection of health-related substances have attracted great attention. Because the natural environment and human environment are complex and difficult to repair, it is of great practical significance to construct a fast and nondestructive method for the preparation and nondestructive detection of controllable catalysts with high cyclic catalytic efficiency and catalytic activity. With the development of nanotechnology, the magnetic response of magnetic nanomaterials to external magnetic field has important research value in solving the above problems. In this thesis, the cyclic controlled catalytic degradation and surface enhanced Raman scattering (SERSs) nondestructive analysis of magnetic nanocomposites based on gold nanoparticles-AuNPsO / silver nanoparticles-silver nanospheres have been studied in this paper. The specific contents are as follows: (1) We have designed and prepared a class of magnetically responsive nanocomposites. The characterization of the magnetic hysteresis regression line confirmed the successful synthesis of magnetic nanocomposites of two different sizes (600 nm and 40 nm). The loading effect of metal nanoparticles is good, the particle size distribution is uniform, the dispersion in water is good, and the magnetic saturation is as high as 59emugr / g. (2) based on the magnetic response and catalytic properties of magnetic nanomaterials, we applied them to the reduction and degradation of methylene blue (MBB) by NaBH4, and investigated their catalytic properties. In our experiment, the catalytic performance of Fe3O4-13 nm-AuNPs is the best, and the catalytic degradation rate of MB can reach 922% in only 5 min. At the same time, the catalytic performance and morphology of the catalyst showed little change in the three cycles of cyclic catalytic degradation reaction. In addition, the long term stability of the catalyst was good, and the catalytic activity of the catalyst remained almost unchanged after being preserved in powder form for 6 months. (3) further, we investigated the surface enhanced Raman spectroscopy (SERS) properties of Fe3O4-30nm-AuNPsF3O4-AuNIs and Fe3O4-AgNPs. The SERS properties of Fe3O4-AuNIs and Fe3O4-AgNPs were superior to those of Fe3O4-30 nm-AuNPs, indicating that the composition and morphology of the substrates had an effect on the SERS. However, the preparation of Fe3O4-AuNIs is easier to oxidize the Ag in Fe304-AgNPs. Therefore, in the follow-up study, we selected Fe3O4-30nm-AuNPs as the enhancement substrate, and the detection sensitivity was up to 10 nm in the detection of Rhodamine 6G (R6G) by SERS.
【学位授予单位】：华东师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB33

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