Facet-Dependent in Situ Growth of Nanoparticles in Epitaxial Thin Films: The Role of Interfacial Energy
Facet-Dependent in Situ Growth of Nanoparticles in Epitaxial Thin Films: The Role of Interfacial Energy
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DOI：
10.1021/jacs.9b02283
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发表时间：
2019-05-08
影响因子：
15
通讯作者：
Choi, Gyeong Man
中科院分区：
文献类型：
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作者：
Kim, Kun Joong;Han, Hyeon;Choi, Gyeong Man
利用出溶现象使纳米颗粒成核是设计用于催化和可再生能源的耐用和活性材料的一种有前途的途径。在这里，我们专注于主晶格的表面取向上的成核动力学的影响，以解决问题，关于“优先成核网站”。为此，我们对三种不同取向的钙钛矿薄膜进行了系统的模型研究。值得注意的是，与先前基于散装粉末的研究表明（110）表面是出溶的优选平面相反，我们确定其他平面如（001）和（111）-刻面也显示出强烈的出溶。此外，颗粒尺寸和表面覆盖率根据表面取向而显著变化。在取向膜中，（111）取向膜的出溶产生的颗粒数量最多，颗粒尺寸最小，嵌入最深，颗粒间距最小且最均匀。基于经典的成核理论，我们阐明了作为衬底取向的函数的界面能的差异在控制出溶纳米颗粒的独特形态和成核行为中起着至关重要的作用。我们的发现为可调固态催化剂或纳米金属装饰提出了新的设计原则。
Nucleation of nanoparticles using the exsolution phenomenon is a promising pathway to design durable and active materials for catalysis and renewable energy. Here, we focus on the impact of surface orientation of the host lattice on the nucleation dynamics to resolve questions with regards to "preferential nucleation sites". For this, we carried out a systematic model study on three differently oriented perovskite thin films. Remarkably, in contrast to the previous bulk powder-based study suggesting that the (110) surface is a preferred plane for exsolution, we identify that other planes such as (001)- and (111)-facets also reveal vigorous exsolution. Moreover, particle size and surface coverage vary significantly depending on the surface orientation. Exsolution of (111)-oriented film produces the largest number of particles, the smallest particle size, the deepest embedment, and the smallest and most uniform interparticle distance among the oriented films. Based on classic nucleation theory, we elucidate that the differences in interfacial energies as a function of substrate orientation play a crucial role in controlling the distinct morphology and nucleation behavior of exsolved nanoparticles. Our finding suggests new design principles for tunable solid-state catalyst or nanoscale metal decoration.