Templated Growth of a Homochiral Thin Film Oxide
Templated Growth of a Homochiral Thin Film Oxide
复制标题
同手性薄膜氧化物的模板化生长
DOI：
10.1021/acsnano.0c00398
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发表时间：
2020
期刊：
影响因子：
17.1
通讯作者：
Coughlin, Benjamin P.
中科院分区：
文献类型：
--
作者：
Schilling, Alex C.;Therrien, Andrew J.;Hannagan, Ryan T.;Marcinkowski, Matthew D.;Kress, Paul L.;Patel, Dipna A.;Balema, Tedros A.;Larson, Amanda M.;Lucci, Felicia R.;Coughlin, Benjamin P.
手性表面对于对映选择性吸附和反应越来越感兴趣。虽然金属表面可以制备具有多种手性表面取向，但手性氧化物表面制备更具挑战性。我们证明金属表面的手性可用于指导薄膜手性氧化物的同手性生长。具体来说，我们研究了手性“29”氧化铜，它是通过在 650 K 下氧化 Cu(111) 单晶而形成的。表面结构展开的单晶暴露了表面取向的连续分布，作为晶体上位置的函数，使我们能够利用高分辨率扫描隧道显微镜系统地研究金属和表面氧化物之间的手性传递机制。我们发现局部底层金属面引导氧化物覆盖层的方向和手性。重要的是，在模板生长的 Cu 台阶边缘相距≤20 nm 的区域中发现了“29”氧化物的单个同手性域。我们利用这些信息来选择 Cu(239 241 246) 取向的单晶，并证明通过根据底层金属晶体的微妙手性进行模板化，可以在同手性域中生长“29”氧化物表面。这项工作展示了如何通过氧化放大由金属表面轻微取向错误（~1 个位点/20 nm2）引起的小程度手性，以产生具有规则的手性氧化物孔阵列（~75 个位点/20 nm2）的纯手性氧化物。这提供了一种通过适当“误切”金属表面的氧化来制造手性氧化物表面的通用方法。
Chiral surfaces are of growing interest for enantioselective adsorption and reactions. While metal surfaces can be prepared with a wide range of chiral surface orientations, chiral oxide surface preparation is more challenging. We demonstrate the chirality of a metal surface can be used to direct the homochiral growth of a thin film chiral oxide. Specifically, we study the chiral “29” copper oxide, formed by oxidizing a Cu(111) single crystal at 650 K. Surface structure spread single crystals, which expose a continuous distribution of surface orientations as a function of position on the crystal, enable us to systematically investigate the mechanism of chirality transfer between the metal and the surface oxide with high-resolution scanning tunneling microscopy. We discover that the local underlying metal facet directs the orientation and chirality of the oxide overlayer. Importantly, single homochiral domains of the “29” oxide were found in areas where the Cu step edges that templated growth were ≤20 nm apart. We use this information to select a Cu(239 241 246) oriented single crystal and demonstrate that a “29” oxide surface can be grown in homochiral domains by templating from the subtle chirality of the underlying metal crystal. This work demonstrates how a small degree of chirality induced by slight misorientation of a metal surface (∼1 sites/20 nm2) can be amplified by oxidation to yield a homochiral oxide with a regular array of chiral oxide pores (∼75 sites/20 nm2). This offers a general approach for making chiral oxide surfaces via oxidation of an appropriately “miscut” metal surface.