Abstract

Using the in-situ liquid cell transmission electron microscopy, the three-stage growth of Pt₃Ni-Ni(OH)₂ core-shell structures at the gas-liquid interfaces was clearly observed, which consists of (1) a thermodynamically driven Pt₃Ni alloy core by the monomer attachment, (2) a nickel (Ni) shell formation due to the depletion of the Pt salt precursor, and (3) the oxidation and of the Ni shell into Ni(OH)₂ flakes. We also further observed the nucleation and growth of the Ni(OH)₂ flakes on an existing layer either at the middle part or at the step edge. More interestingly, the dynamic transformation among a Pt₃Ni alloy, Ni clusters and Ni(OH)₂ flakes was also imaged even at a high electron dose rate.

中文翻译：

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通过原位液体电池TEM跟踪气液界面Pt 3 Ni-Ni（OH）2核-壳结构的原子路径

摘要

使用原位液体细胞透射电子显微镜，可以清楚地观察到Pt ₃ Ni-Ni（OH）₂核-壳结构在气液界面的三阶段生长，其中包括（1）由热力学驱动的Pt ₃镍合金芯通过单体附着，（2）由于Pt盐前体的耗尽而形成镍（Ni）壳，以及（3）氧化和Ni壳氧化成Ni（OH）₂薄片。我们还进一步观察了Ni（OH）₂薄片在中间部分或台阶边缘的现有层上的形核和生长。更有趣的是，Pt ₃ Ni合金，Ni团簇和Ni（OH）₂之间的动态转变 即使在高电子剂量率下，薄片也能成像。