Bian Zhiyun, Nakano Yuki, Miyata Keisuke, Oya Ichiro, Nobuoka Masaki, Tsutsui Yusuke, Seki Shu, Suda Masayuki
Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto, 615-8510, Japan.
JST-PRESTO, Honcho 4-1-8, Kawaguchi, Saitama, 332-0012, Japan.
Adv Mater. 2023 Nov;35(48):e2306061. doi: 10.1002/adma.202306061. Epub 2023 Oct 25.
The emergence of the chiral-induced spin-selectivity (CISS) effect offers a new avenue for chiral organic molecules to autonomously manipulate spin configurations, thereby opening up possibilities in spintronics and spin-dependent electrochemical applications. Despite extensive exploration of various chiral systems as spin filters, one often encounters challenges in achieving simultaneously high conductivity and high spin polarization (SP). In this study, a promising chiral van der Waals superlattice, specifically the chiral TiS crystal, is synthesized via electrochemical intercalation of chiral molecules into a metallic TiS single crystal. Multiple tunneling processes within the highly ordered chiral layered structure of chiral TiS superlattices result in an exceptionally high SP exceeding 90%. This remarkable observation of significantly high SP within the linear transport regime is unprecedented. Furthermore, the chiral TiS electrode exhibits enhanced catalytic activity for oxygen evolution reaction (OER) due to its remarkable spin-selectivity for triplet oxygen evolution. The OER performance of chiral TiS superlattice crystals presented here exhibits superior characteristics to previously reported chiral MoS catalysts, with an approximately tenfold increase in current density. The combination of metallic conductivity and high SP sets the stage for the development of a new generation of CISS materials, enabling a wide range of electron spin-based applications.
手性诱导自旋选择性（CISS）效应的出现为手性有机分子自主操纵自旋构型提供了一条新途径，从而为自旋电子学和自旋相关电化学应用开辟了可能性。尽管人们对各种手性体系作为自旋过滤器进行了广泛探索，但在同时实现高电导率和高自旋极化（SP）方面常常遇到挑战。在本研究中，通过将手性分子电化学插入金属TiS单晶中，合成了一种有前景的手性范德华超晶格，即手性TiS晶体。手性TiS超晶格高度有序的手性层状结构内的多个隧穿过程导致了超过90%的异常高的SP。在线性输运 regime 内显著高的SP这一非凡观察结果是前所未有的。此外，手性TiS电极由于其对三重态析氧的显著自旋选择性，对析氧反应（OER）表现出增强的催化活性。这里展示的手性TiS超晶格晶体的OER性能表现出优于先前报道的手性MoS催化剂的特性，电流密度增加了约十倍。金属导电性和高SP的结合为新一代CISS材料的开发奠定了基础，从而实现了广泛的基于电子自旋的应用。
