核壳型纳米铁-银双金属粉末的制备研究

核壳型纳米铁-银双金属粉末的制备研究(6700字)
摘  要：本文以AgNO3为主盐，聚乙烯吡咯烷酮(PV P)为分散剂，采用直接置换法制备了核壳型纳米铁-银双金属粉末，探讨了制备过程中的各个工艺条件。利用透射电子显微镜、扫描电子显微镜、X 射线衍射仪和X射线荧光光谱等仪器对粉末的形貌、物相结构及表面成分进行进行了表征。结果表明：纳米铁-银双金属粒子呈现圆球形，相互连接成链状，具有核壳型结构，在20~100nm范围内均匀分布，平均粒径约40 nm，单个粒子大小随Ag含量的增加而有所增大，颗粒分散性较好。在制备反应中加入适量的PV P高分子分散剂能够改善粉末的形态与团聚程度，并且不会增大溶液粘度。因此，本实验中PVP的用量应控制在1~2 g范围内。
关键词：铁-银；纳米双金属；核壳型；置换法

The Research of the Preparation of Fe-Ag core-shell Bimetallic Nanoparticles
Abstract: The present study described the successful preparation of Fe-Ag nanoparticles with core-shell structure by reduction and deposition of Ag on nanoscale Fe surface, which used AgNO3  as mainly salt and polyvinyl pyrrolidone (PVP) as dispersing agents. The technology conditions during the preparation were also discussed. The morphology, phase structure and surface composition of Fe-Ag core-shell nanoparticles were further characterized by BET, XRD, TEM, SEM, X-ray fluorescence and X-ray photo-electron spectroscopy. The result shows that the Fe-Ag nanoparticles is core-shell with average particle size about 40 nm. The single particle size increases obviously with the increase of Ag concentration, which distributes in the range of 20~100 nm and has good dispersity. The morphology and the aggregation of nano-powder could be improved by the addition of PVP during the reaction, and do not increase the solution viscosity. In this experiment, PVP dosage should be controlled in the range of 1g~2g.
Keyword: Fe-Ag；bimetallic nanoparticles；core-shell；displacement

目    录
摘  要：    I
关键词：    I
1  前言    2
1.1  研究工作的背景    2
1.2  核-壳纳米双金属的制备研究    2
1.3  直接置换法研究现状    2
1.4  论文的主要研究内容    3
2  实验部分    3
2.1  纳米Fe-Ag双金属粉末的制备    3
2.2  纳米Fe-Ag双金属粉末的表征    4
2.3  结果和讨论    4
2.3.1  纳米Fe-Ag双金属粉末的组成和结构    4
2.3.2  直接置换法制备纳米Fe- Ag双金属粉末工艺条件的探讨    5
3  结果与讨论    9
4  展 望    9
参考文献    9