Temperature-Induced Interfacial Change in Au@SiO2 Core-Shell Nanoparticles Detected by Extended X-ray Absorption Fine Structure
Temperature-Induced Interfacial Change in Au@SiO2 Core-Shell Nanoparticles Detected by Extended X-ray Absorption Fine Structure
复制标题
通过扩展 X 射线吸收精细结构检测 Au@SiO2 核壳纳米粒子中温度引起的界面变化
DOI：
10.1021/jp907815b
复制
发表时间：
2010-01-14
影响因子：
3.7
通讯作者：
Wu, Zhonghua
中科院分区：
文献类型：
--
作者：
Zhang, Kunhao;Wang, Wei;Wu, Zhonghua
核壳纳米粒子由于其潜在的应用前景而受到广泛的研究。然而，关于其界面结构及其稳定性的报道很少。本文采用溶胶-凝胶法制备了Au@SiO2纳米粒子。利用原位扩展X射线吸收精细结构技术研究了其结构随温度的变化。发现当温度高于600 ℃时，Au核与二氧化硅壳层之间的界面键由Au-N键转变为Au-Si键。在Au核和二氧化硅壳之间具有Au-Si键的Au-二氧化硅界面可以在600 ~ 1000 ℃的温度范围内稳定存在。描述了键变的机理。在Au@SiO2核壳体系中，Au纳米粒子的热膨胀系数为1.4 × 10（-5）K-1，与体相Au的热膨胀系数基本相同。本文详细讨论了结构变化和热膨胀行为。
Core-shell nanoparticles were widely studied because of their potential application. However, there are few reports about the interfacial structure and its stability. In this paper, Au@SiO2 nanoparticles have been synthesized by using the traditional sol-gel method. In situ extended X-ray absorption fine structure technique was used to characterize the structural change with temperature. It is found that the interfacial bonding between the Au core and the silica shell has changed from a Au-N bond to a Au-Si bond when the temperature is above 600 degrees C. The Au-silica interface with Au-Si bonds between the Au core and silica shell can be stably existed in the temperature range of 600 to 1000 degrees C. The mechanism of bond change is described. The thermal expansion coefficient of Au nanoparticles in the Au@SiO2 core-shell system is obtained to be 1.4 x 10(-5) K-1, which is almost the same with Au bulk. The details of the structural changes and thermal expansion behavior are discussed in this paper.