如何将Ag纳米球转化为AgAu纳米
Liane M Moreau1, Charles A Schurman1, Sumit Kewalramani1
1Department of Materials Science and Engineering, ‡Department of Biomedical Engineering, §Department of Chemistry, ∥Department of Physics and Astronomy, and ⊥International Institute for Nanotechnology, Northwestern University , Evanston, Illinois 60208, United States.
Journal of the American Chemical Society
|August 12, 2017
概括
研究人员发现了制造双金属空心纳米粒子的原子尺度机制. 这种对纳米级电磁交换的新理解解释了银金纳米的形成,促进了它们在生物医学和催化应用中的使用.
科学领域:
- 材料科学
- 纳米技术
- 化学学
背景情况:
- 双金属空洞,多孔的贵金属纳米粒子对于生物医学,光学和催化应用至关重要.
- 目前的制备方法,如与HAuCl4反应的银颗粒,缺乏对形成机制的明确原子尺度理解.
- 现有的解释,比如纳米级的基肯达尔效应或批量电交换,不足以解释观察到的现象.
研究的目的:
- 阐明二金属空心纳米粒子形成的原子尺度机制.
- 研究银纳米球转化为银金纳米的过程.
- 提出一个精细的机制,准确地描述纳米尺度上的空洞化过程.
主要方法:
- 在现场采用纳米和原子尺度的特征技术.
- 技术包括X射线吸收细结构 (XAFS),小角度X射线散射 (SAXS),X射线光 (XRF) 和电子显微镜.
- 这些方法允许实时监测银纳米圈与HAuCl4之间的反应.
主要成果:
- 该研究确定了酸盐覆盖的银纳米球转化为银金纳米圈的可信反应途径.
- 发现空洞化机制与纳米基肯德尔效应和电交换不同.
- 提出了一种改进的纳米级电交换工艺,考虑到纳米级特定的考虑因素.
结论:
- 双金属空洞纳米颗粒的形成涉及一种新的纳米尺度的电磁交换机制.
- 这种机制准确地解释了观察到的形态和化学变化,特别是空洞化过程.
- 这些发现为设计和合成这些先进的纳米材料提供了至关重要的基础知识.
相关概念视频
Voltaic/Galvanic Cells
Spontaneous Chemical Reactions
Spontaneous redox reactions occur abundantly in nature. The chemical reaction occurring in a disposable AA battery powering our remote controls is one such example of a spontaneous redox reaction. Another example is the immersion of coiled copper wire into an aqueous silver nitrate solution. The reaction shows a gradual, visually impressive color change from colorless to bright blue and the formation of a grey precipitate on the copper wire. In this experiment,...
Spontaneous redox reactions occur abundantly in nature. The chemical reaction occurring in a disposable AA battery powering our remote controls is one such example of a spontaneous redox reaction. Another example is the immersion of coiled copper wire into an aqueous silver nitrate solution. The reaction shows a gradual, visually impressive color change from colorless to bright blue and the formation of a grey precipitate on the copper wire. In this experiment,...
Inductively Coupled Plasma Atomic Emission Spectroscopy: Instrumentation
Inductively coupled plasma (ICP) is the common plasma source used in atomic emission spectroscopy (AES), a technique that detects and analyzes various elements in a sample. This method is often called inductively coupled plasma atomic emission spectroscopy (ICP-AES).
There are three main types of inductively coupled plasma atomic emission spectroscopy (ICP-AES) instruments: sequential, simultaneous multichannel, and Fourier transform instruments, with the latter being less commonly used.
There are three main types of inductively coupled plasma atomic emission spectroscopy (ICP-AES) instruments: sequential, simultaneous multichannel, and Fourier transform instruments, with the latter being less commonly used.
Atomic Fluorescence Spectroscopy
Atomic fluorescence spectroscopy (AFS) is an analytical technique that involves the electronic transitions of atoms in a flame, furnace, or plasma being excited by electromagnetic (EM) radiation. When these atoms absorb energy, they become excited and subsequently release energy as they return to their original state. This emitted light, or "fluorescence," is observed at a right angle to the incident beam. Both absorption and emission processes transpire at distinct wavelengths, which are...


