Ordered Structures and Morphology-Induced Phase Transitions at Graphite‒Acetonitrile Interfaces
Ordered Structures and Morphology-Induced Phase Transitions at Graphite‒Acetonitrile Interfaces
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石墨与乙腈界面的有序结构和形态诱导的相变
DOI：
10.1021/acs.jpcc.9b06440
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Yang, Ding-Shyue
中科院分区：
文献类型：
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作者：
Wu, Chengyi;Yang, Ding-Shyue
在这份报告中，反射高能电子衍射作为一种直接的结构探测方法被用来揭示一个意想不到的垂直有序和长程结晶界面乙腈物理吸附在高取向热解石墨（HOPG），其组装结构是相关的电池的进一步发展。即使在这种固体分子系统中没有显著的引导力，HOPG的表面形态和平台在分子有序中起着至关重要的作用，作为晶格匹配模板效应的结果。更令人惊讶的是，第一次观察到两种乙腈多晶型物之间的相变完全是由于HOPG的表面形貌。通过仔细检查的晶体结构，界面有序和结构转变可以理解为动力学控制的奥斯特瓦尔德过程和热力学能量之间的竞争的结果。最后，目前的观察增加了安装的证据，需要明确考虑到表面形态的HOPG和独特的强度的反射电子衍射界面的研究。
In this report, reflection high-energy electron diffraction as a direct structure-probing method is used to reveal an unanticipated vertical ordering and long-range crystallinity in interfacial acetonitrile physisorbed on highly oriented pyrolytic graphite (HOPG), whose assembly structures are relevant to further development of batteries. Even without significant guiding forces in this solid–molecule system, the surface morphology and terraces of HOPG play a critical role in molecular ordering as a result of the lattice-matching template effect. More surprisingly, a phase transition between two acetonitrile polymorphs solely due to surface topography of HOPG is observed for the first time. By careful examination of the crystal structures, the interfacial ordering and the structural transition can be understood as the results of a competition between the kinetically controlled Ostwald process and thermodynamic energetics. Finally, the present observations add to the mounting evidence for the need to explicitly take surface morphology of HOPG into consideration and the unique strength of reflection electron diffraction for interfacial studies.