1T′-Transition Metal Dichalcogenide Monolayers Stabilized on 4H-Au Nanowires for Ultrasensitive SERS Detection

08 Apr 2024

Published on Nature Materials (8 April 2024)

Author(s): Zijian Li, Li Zhai, Qinghua Zhang, Wei Zhai, Pai Li, Bo Chen, Changsheng Chen, Yao Yao, Yiyao Ge, Hua Yang, Panzhe Qiao, Jianing Kang, Zhenyu Shi, An Zhang, Hongyi Wang, Jinzhe Liang, Jiawei Liu, Zhiqiang Guan, Lingwen Liao, Vlad Andrei Neacșu, Chen Ma, Ye Chen, Ye Zhu, Chun-Sing Lee, Lu Ma, Yonghua Du, Lin Gu, Jian-Feng Li, Zhong-Qun Tian, Feng Ding & Hua Zhang

Abstract

Unconventional 1T′-phase transition metal dichalcogenides (TMDs) have attracted tremendous research interest due to their unique phase-dependent physicochemical properties and applications. To date, various synthetic strategies have been developed to prepare 1T′-TMDs. However, the aforementioned synthetic approaches still suffer from harsh synthetic conditions or complicated synthetic protocols, it is important to develop a mild and rapid method to prepare 1T′-TMDs with high phase purity.
Au substrates/templates are widely used as ideal substrates/templates for the controllable growth of high-quality TMD monolayers (MLs), which, however, normally possess a pure 2H phase, or mixed phase of 1T′ and 2H. In addition, due to its metastable nature, the semi-metallic 1T′ phase prepared via the aforementioned methods could gradually transform into the thermodynamically stable semiconducting 2H phase, severely hindering the study of intrinsic physicochemical properties and phase-dependent applications of 1T′-TMDs.
In this work, we report that the unconventional 4H-Au nanowires (NWs), when used as templates, can induce the quasi-epitaxial growth of high phase-purity and stable 1T′-TMD MLs, including WS2, WSe2, MoS2 and MoSe2, via a facile and rapid wet-chemical method. Systematic characterization and calculation results reveal that the formation and stabilization of high phase-purity 1T′-TMD MLs on the 4H-Au NWs could be ascribed to their strong interaction, charge doping from the oleylamine in solution, and the unique 4H phase of Au template. The as-synthesized 4H-Au@1T′-TMD core-shell NWs can be used for ultrasensitive surface-enhanced Raman scattering (SERS) detection. For instance, the 4H-Au@1T′-WS2 NWs have achieved attomole-level SERS detections of Rhodamine 6G and a variety of SARS-CoV-2 spike proteins. This work provides new insights into the preparation of high phase-purity and stable 1T′-TMD MLs on metal substrates/templates, showing great potential in various promising applications.

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