CAS OpenIR  > 研究所(批量导入)
Alternative TitleNanocomposites of Chalcogenide Semiconductor and Noble Metals
Thesis Advisor丁玉龙 ; 杨军
Degree Grantor中国科学院研究生院
Degree Discipline化学工程
Keyword硫族化物   复合纳米材料   相转移法   沉积模式   奥斯特瓦尔德熟化
Abstract将不同类别的成分集成在一起,实现材料的功能化是纳米材料合成领域的一个重要方向。由于硫族化物-贵金属复合纳米材料在纳米体系中集成了性能差异明显的不同成分,并且在纳米尺度上各组分之间产生强相互作用,所以复合结构纳米材料突破了单一组分材料性能的局限,不仅具有明显增强的本征性能,而且还表现出许多奇特性能,在光、电、催化、制药及功能材料等方面有广阔的应用前景。 本论文在合成高质量硫族化物半导体纳米颗粒的基础上,采用普遍化金属离子相转移法制备了几种典型的硫族化物-贵金属复合纳米材料,研究贵金属在半导体纳米颗粒表面的沉积模式,探索复合材料的生长机理,为材料的进一步应用作基础性研究准备。主要成果包括: 1.制备出高质量的半导体纳米颗粒,是合成半导体-贵金属复合纳米材料的基础。我们采用有机液相合成中常见的“热注射”法,结合文献报道的制备方法,我们做了适当修改,制备出了较高量子产率、尺寸分布均匀、形状易控的硫族化物半导体纳米颗粒,为合成复合纳米材料的研究做了一个初步的工作。 2.我们利用普遍化金属离子相转移方法制备出硫族化物-Au复合纳米材料,讨论了Au在半导体纳米颗粒上沉积模式与半导体纳米颗粒的种类及尺寸的关系,并且在合成中发现半导体材料和Au前驱体摩尔比改变时Au在纳米颗粒表面的Ostwald熟化现象,以及Au在PbSe纳米颗粒表面生长有个上限,该发现是我们首次所报道。 3.在制备PbS和Ag及Au复合材料体系时,我们发现,分别将Ag和Au在PbS纳米颗粒表面沉积及Ag和Au依次沉积的结果是我们所预想的,而将Ag和Au的沉积次序反过来,获得的结果和预想的显著不同。我们得到的结论是:无论Ag和Au以怎样的次序沉积,最后都能观察到一样的结果,即在PbS纳米颗粒表面包覆的Ag2S壳层上Au只在一处沉积。
Other AbstractA key frontier in nanomaterial fabrication is the integration of different materials within the same structure as a means to increase functionality. Since the nanocomposites of chalcogenide semiconductor and noble metals combine materials with distinctly different physical and chemical properties, and strong interactions between the nanoscale metal and semiconductor components, this type of nanostructure breakthroughs the limitation of single material properties to yield a unique hybrid nanosystem with multifunctional capabilities and tunable or enhanced properties that may not be attainable otherwise. The nanocomposites of chalcogenide semiconductor and noble metals may find broad applications in optics, electricity, catalysis, pharmaceuticals, and functional materials. In this thesis, we synthesize several typical nanocomposites of chalcogenide semiconductor and noble metals based on the general phase-transfer protocol for metal ions. The protocol involves the synthesis of high-quality chalcogenide semiconductors in organic solvents and the subsequent integration with noble metals. For basic research to prepare for the further application of the nanomaterials, we herein focus on the deposition mode of noble metals on the surface of chalcogenide semiconductor nanocrystals and the growth mechanism of the composite nanomaterials. The experimental results obtained are summarized as following: 1. Preparation of high quality semiconductor nanocrystals is the basis for the synthesis of semiconductor-noble metal nanocomposites. Upon the common “hot injection” method, a wide variety of chalcogenide semiconductor nanocrystals with high crystallinity, uniform size distribution, and controllable shape have been synthesized, which are crucial for the subsequent synthesis of nanocomposites. 2. The nanocomposites consisting of chalcogenide semiconductor and gold are synthesized based on the general phase-transfer protocol for metal ions, and the relationship between the deposition mode of gold and the properties of the semiconductor nanocrystals (such as the type and the size) is discussed. As a result, we find that Ostwald ripening of Au on the surface of nanocrystals occurs with the increase of Au molar ratio during the synthesis. And the experimental results definitely manifest that there is an upper size limit for the growth of Au on the surface of the PbSe nanocrystals. We believe that this important feature was not observed before in growth of noble metals on different kinds of semiconductor nanocrystals. 3. In the preparation of PbS-Ag/Au nanocomposites system, we find the mode for depositing of Ag or Au independently on the surface of PbS nanocrystals can be predicted. However, the results are significantly different from what we expect when both Ag and Ag are deposited; the same PbS-Ag/Au nanocomposites, in which only a single Au domain is grown on the core-shell PbS-Ag2S nanocrystals, can be observed regardless of the order of Ag and Au deposition on the surface of PbS nanocrystals.
Document Type学位论文
Recommended Citation
GB/T 7714
胡威威. 硫族化物-贵金属复合纳米材料的研究[D]. 中国科学院研究生院,2013.
Files in This Item:
File Name/Size DocType Version Access License
硫族化物-贵金属复合纳米材料的研究.pd(2566KB) 限制开放CC BY-NC-SAApplication Full Text
Related Services
Recommend this item
Usage statistics
Export to Endnote
Google Scholar
Similar articles in Google Scholar
[胡威威]'s Articles
Baidu academic
Similar articles in Baidu academic
[胡威威]'s Articles
Bing Scholar
Similar articles in Bing Scholar
[胡威威]'s Articles
Terms of Use
No data!
Social Bookmark/Share
All comments (0)
No comment.

Items in the repository are protected by copyright, with all rights reserved, unless otherwise indicated.