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从非金属Au246转变为金属Au279,具有新生的表面等离子共振
Tatsuya Higaki1, Meng Zhou1, Kelly J Lambright2
1Department of Chemistry , Carnegie Mellon University , Pittsburgh , Pennsylvania 15213 , United States.
Journal of the American Chemical Society
|April 17, 2018
概括
原子精确的金纳米集群 (Au279) 与较小的集群不同,表现出金属性质. 这一发现为金属纳米颗粒从激电状态到等离子状态的过渡提供了新的见解.
科学领域:
- 纳米技术
- 材料科学
- 物理化学
背景情况:
- 金属纳米颗粒的光学特性具有重要意义.
- 对于金属纳米粒子研究来说,理解从激电状态到等离子状态的过渡至关重要.
- 准备大于2纳米的原子精确纳米粒子是一个重大挑战.
研究的目的:
- 合成和表征一个原子精确的金纳米集群 (Au279(SR) 84).
- 研究黄金纳米集群中从非金属到金属电子结构的转变.
- 探索Au279纳米团的光学特性和表面等离子体共振 (SPR) 行为.
主要方法:
- 合成原子精确的Au279 ((SR) 84纳米集群.
- 用于分析激发状态动态的Femtosecond暂时吸收光谱.
- 静态吸收光谱用于在不同温度下研究光学特性.
主要成果:
- Au279纳米集群显示了激光功率依赖的激发状态寿命,表明金属状态.
- 这与在较小的Au246(SR) 80纳米集群中观察到的非金属电子结构形成鲜明对比.
- Au279纳米团在506纳米处呈现出新生的等离子波段,没有显著的峰值转移到60K,与等离子波的行为一致.
结论:
- 在Au246和Au279纳米团之间观察到从非金属到金属行为的急剧转变.
- Au279纳米团显示金属纳米粒子的特征,包括等离子体的行为.
- 这些发现为未来关于金属纳米集群中的电子转换和等离子形成的理论研究提供了基础.
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