在Au-Pd核心外纳米颗粒的现场动力和热力学增长控制
Shu Fen Tan1,2, Geeta Bisht1,2, Utkarsh Anand1,2
1Department of Physics , National University of Singapore , Singapore 117551.
Journal of the American Chemical Society
|August 14, 2018
概括
研究人员使用现场传输电子显微镜探索金核心外纳米粒子的形成. 通过影响外生长机制来控制纳米粒子形状的反应温度,从而实现更大的设计灵活性.
科学领域:
- 材料科学
- 纳米技术
- 物理化学
背景情况:
- 一湿化学合成提供了对纳米粒子 (NP) 具有可控形状和组成的直接途径.
- 了解NP形成机制对于精确的合成至关重要,但在实验上具有挑战性.
研究的目的:
- 在不同的反应条件下研究金 (Au) 芯- (Pd) NP的形成机制.
- 阐明反应温度在控制NP形状和生长中的作用.
主要方法:
- 使用现场液体细胞传导电子显微镜 (TEM) 来动态观察NP的形成.
- 改变反应温度以研究动力学和热力学控制的合成模式.
主要成果:
- 证明了Au-Pd NP的温度依赖形状调整,将纳米棒转化为箭头或立方体核心外结构.
- 观察到反应温度在动力学和热力学主导路径之间切换贝的生长.
- 确定封装剂的封装和沉积原子的面向选择在不同的动力条件下决定了的形成.
结论:
- 对温度驱动的NP形成的机械洞察力可以加强对形状和组成的控制.
- 这项研究为各种技术应用合成量身定制的纳米粒子提供了基础.
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