Chen Peng-Cheng, Liu Mohan, Du Jingshan S, Meckes Brian, Wang Shunzhi, Lin Haixin, Dravid Vinayak P, Wolverton Chris, Mirkin Chad A
Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208, USA.
International Institute for Nanotechnology, Northwestern University, Evanston, IL 60208, USA.
Science. 2019 Mar 1;363(6430):959-964. doi: 10.1126/science.aav4302.
Nanomaterials that form as heterostructures have applications in catalysis, plasmonics, and electronics. Multielement nanoparticles can now be synthesized through a variety of routes, but how thermodynamic phases form in such structures and how specific interfaces between them can be designed and synthesized are still poorly understood. We explored how palladium-tin alloys form mixed-composition phases with metals with known but complex miscibilities. Nanoparticles with up to seven elements were synthesized, and many form triphase heterostructures consisting of either three-interface or two-interface architectures. Density functional theory calculations and experimental work were used to determine the balance between the surface and interfacial energies of the observed phases. From these observations, design rules have been established for making polyelemental systems with specific heterostructures, including tetraphase nanoparticles with as many as six junctions.
形成异质结构的纳米材料在催化、等离子体学和电子学领域有应用。现在可以通过多种途径合成多元素纳米颗粒，但在这类结构中热力学相如何形成以及它们之间的特定界面如何设计和合成仍知之甚少。我们探究了钯 - 锡合金如何与具有已知但复杂混溶性的金属形成混合成分相。合成了含有多达七种元素的纳米颗粒，许多形成了由三界面或两界面结构组成的三相异质结构。利用密度泛函理论计算和实验工作来确定所观察到的相的表面能和界面能之间的平衡。基于这些观察结果，已经建立了用于制造具有特定异质结构的多元素体系的设计规则，包括具有多达六个结的四相纳米颗粒。
