β-FeOOH制备及其还原过程研究

发布时间：2018-06-15 13:02

  本文选题：β-FeOOH + H_2　； 参考：《安徽大学》2015年硕士论文

【摘要】：β-FeOOH是一种性能优良的功能材料,可用作颜料、催化剂、磁记录介质的前驱体、磁性涂料和气体传感器等。同时,β-FeOOH是合成各种磁性材料(如Fe3O4、γ-Fe2O3和Fe等)的良好前驱体。例如,录像磁带中使用的磁性微粒(铁或γ-Fe2O3)就是β-FeOOH前驱体在高温锻烧后获得的。该方法获得的磁性材料性能优良且成本低廉,因此,应用前景好。然而,β-FeOOH前驱体的控制合成、还原过程及其产物转化工艺在当前还值得继续探究。本文结合环境友好与还原的特点,侧重开展了 β-FeOOH的改性与制备,并尝试实现以β-FeOOH为前驱体生产各种磁性纳米材料；研究了其还原特性与产物转化技术；探索了各种磁性转化产物可能的机理等等。本文的主要工作内容如下：1.介绍β-FeOOH的研究现状,对常用的制备方法、目前的主要研究方向、β-FeOOH与其他铁系氧化物的关系、β-FeOOH的主要应用与结构特点等方面做了详细的介绍,在归纳与总结的基础上对本文的研究内容提出可行的方案。2、采用不同合成方法,成功设计、制备出了5种形态的β-FeOOH纳米晶；实现了稳定合成多种形态的β-FeOOH纳米材料。对所得的产物进行了XRD、 SEM. TGA等表征,对比分析它们的差异。3、研究了常压H2气氛中,还原温度为100℃-650℃,实验制备出的P-FeOOH纳米晶的还原过程,主要包括：脱水(β-FeOOH→Fe2O3)、部分还原(Fe2O3→Fe3O4)和再完全还原(γ-Fe2O3→Fe3O4/Fe)三个过程,并在β-FeOOH纳米棒的表面实现了部分还原,得到了部分还原产物多晶的Fe3O4。4、针对β-FeOOH纳米晶气压诱导结构转变的可能性,探索了其在硼氢化钠溶液中70℃条件下的还原过程及转变可能机理。发现在一定温度下,密闭的水体系中,一定浓度的硼氢化钠与β-FeOOH纳米晶相互作用,β-FeOOH的转变过程为：β-FeOOH→γ-FeOOH→Fe3O4。在此条件下,能可控获得结构稳定的γ-FeOOH和Fe304两种磁性纳米材料。5、通过葡萄糖的适量添加,实现了BiOCl与P-FeOOH两种纳米材料的有效复合,成功获得了可见光催化性能优异的β-FeOOH/BiOCl复合光催化剂。光催化实验表明,获得的新型复合催化剂能有效降解污水中的甲基橙等有机污染物,在本文的实验中,降解率可达70%左右。6、对所研究的内容进行进一步的总结和梳理,在现有实验成果的基础上对本课题的所需继续进行的工作提出合理的建议和可行的实验方案,以便后续的研究工作能更顺利地展开。总之,这些工作拓展了β-FeOOH纳米材料的合成和转变方法,通过分别在气相和液相条件下对制备的β-FeOOH纳米晶进行逐步还原探究,加深了对β-FeOOH还原过程的理解,同时也成功的制备出了催化性能优异的β-FeOOH/BiOCl复合纳米材料。这些工作既可为发展磁性材料提供参考,也可望为建立基于可见光催化剂,具有实用价值的有机污染物治理新技术提供新的思路。
[Abstract]:尾 -FeOOH is a functional material with excellent properties. It can be used as precursor of pigment, catalyst, magnetic recording medium, magnetic coating and gas sensor. At the same time, 尾 -FeOOH is a good precursor for the synthesis of various magnetic materials, such as Fe _ 3O _ 4, 纬 -Fe _ 2O _ 3 and Fe. For example, the magnetic particles (iron or 纬 -Fe _ 2O _ 3) used in video tapes are obtained by calcination of 尾 -FeOOH precursors at high temperatures. The magnetic material obtained by this method has good properties and low cost, so it has a good application prospect. However, the controlled synthesis of 尾 -FeOOH precursors, the reduction process and the conversion process of the products are still worthy of further study. According to the characteristics of environmental friendliness and reduction, the modification and preparation of 尾 -FeOOH were carried out, and various magnetic nanomaterials were produced with 尾 -FeOOH as precursor. The possible mechanisms of various magnetic transformation products were explored. The main work of this paper is as follows: 1. The present research situation of 尾 -FeOOH is introduced. The preparation methods, the main research directions, the relationship between 尾 -FeOOH and other iron oxides, the main application and structure characteristics of 尾 -FeOOH are introduced in detail. On the basis of summing up and summing up the research contents of this paper, a feasible scheme. 2. Five kinds of 尾 -FeOOH nanocrystals were successfully designed by different synthesis methods, and various forms of 尾 -FeOOH nanocrystals were synthesized stably. XRD, SEM. The reduction process of P-FeOOH nanocrystals prepared by experiments at 100 鈩，

本文编号：2022095