Fabrication of hollow gold nanoparticles by dewetting, dealloying and coarsening
Fabrication of hollow gold nanoparticles by dewetting, dealloying and coarsening
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DOI：
10.1016/j.actamat.2015.09.024
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发表时间：
2016
期刊：
影响因子：
9.4
通讯作者：
A. Kosinova;Dong Wang;P. Schaaf;O. Kovalenko;L. Klinger;E. Rabkin
中科院分区：
文献类型：
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作者：
A. Kosinova;Dong Wang;P. Schaaf;O. Kovalenko;L. Klinger;E. Rabkin
采用一系列扩散控制过程，即薄膜去湿、去合金化和热粗化，制备空心金纳米粒子。通过对Au-Ag双层膜进行固相去湿处理，然后对Ag进行选择性去合金化，在二氧化硅衬底上制备了多孔金纳米粒子。我们详细研究了所提出的方法的最后一个阶段，使多孔纳米粒子转化为中空的，由于曲率驱动的表面扩散。将多孔纳米颗粒在空气和真空中在350 °C下退火，并通过高分辨率扫描电子显微镜进行表征。通过原位X射线衍射研究了颗粒在热处理过程中的微观结构演变。用Weissmüller-Cahn模型讨论了粗化过程中颗粒压缩应变的减小。与真空退火相比，在环境空气中退火导致金纳米颗粒更快地粗化。在空气中退火的颗粒中观察到被捕获在颗粒本体中的孤立孔以及位于颗粒/基底界面处的孔。一个定性的模型，说明所观察到的粗化行为的建议。
A sequence of diffusion-controlled processes, namely, thin film dewetting, dealloying and thermal coarsening was employed for producing of hollow gold nanoparticles. The porous gold nanoparticles on silica substrate were obtained by solid state dewetting of Au–Ag bi-layers followed by selective dealloying of Ag. We studied in detail the last stage of the proposed method enabling the transformation of porous nanoparticles into hollow ones due to curvature-driven surface diffusion. The porous nanoparticles were annealed at 350 °C in air and in vacuum and characterized by high-resolution scanning electron microscopy. The microstructure evolution of the particles during thermal treatment was studied by in-situ X-ray diffraction. The observed decrease of compressive strain in the particles during coarsening was discussed in terms of Weissmüller–Cahn model. Annealing in ambient air resulted in faster coarsening of gold nanoparticles compared to annealing in vacuum. The isolated pores trapped in the particle bulk as well as the pores located at the particle/substrate interface were observed in the particles annealed in air. A qualitative model illustrating the observed coarsening behavior is proposed.