Chen Junze, Liu Guigao, Zhu Yue-Zhou, Su Min, Yin Pengfei, Wu Xue-Jun, Lu Qipeng, Tan Chaoliang, Zhao Meiting, Liu Zhengqing, Yang Weimin, Li Hai, Nam Gwang-Hyeon, Zhang Liping, Chen Zhenhua, Huang Xiao, Radjenovic Petar M, Huang Wei, Tian Zhong-Qun, Li Jian-Feng, Zhang Hua
Center for Programmable Materials, School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore.
State Key Laboratory of Physical Chemistry of Solid Surfaces, iChEM, Department of Physics, College of Chemistry and Chemical Engineering, and College of Energy, Xiamen University, Xiamen, China.
J Am Chem Soc. 2020 Apr 15;142(15):7161-7167. doi: 10.1021/jacs.0c01649. Epub 2020 Apr 3.
Understanding the reaction mechanism for the catalytic process is essential to the rational design and synthesis of highly efficient catalysts. MoS has been reported to be an efficient catalyst toward the electrochemical hydrogen evolution reaction (HER), but it still lacks direct experimental evidence to reveal the mechanism for MoS-catalyzed electrochemical HER process at the atomic level. In this work, we develop a wet-chemical synthetic method to prepare the single-layer MoS-coated polyhedral Ag core-shell heterostructure (Ag@MoS) with tunable sizes as efficient catalysts for the electrochemical HER. The Ag@MoS core-shell heterostructures are used as ideal platforms for the real-time surface-enhanced Raman spectroscopy (SERS) study owing to the strong electromagnetic field generated in the plasmonic Ag core. The in situ SERS results provide solid Raman spectroscopic evidence proving the S-H bonding formation on the MoS surface during the HER process, suggesting that the S atom of MoS is the catalytic active site for the electrochemical HER. It paves the way on the design and synthesis of heterostructures for exploring their catalytic mechanism at atomic level based on the in situ SERS measurement.
了解催化过程的反应机理对于高效催化剂的合理设计与合成至关重要。据报道，MoS是一种用于电化学析氢反应（HER）的高效催化剂，但仍缺乏直接的实验证据来揭示MoS催化电化学HER过程在原子水平上的机理。在这项工作中，我们开发了一种湿化学合成方法，制备出具有可调尺寸的单层MoS包覆的多面体Ag核壳异质结构（Ag@MoS），作为电化学HER的高效催化剂。由于等离子体Ag核中产生的强电磁场，Ag@MoS核壳异质结构被用作实时表面增强拉曼光谱（SERS）研究的理想平台。原位SERS结果提供了确凿的拉曼光谱证据，证明在HER过程中MoS表面形成了S-H键，这表明MoS的S原子是电化学HER的催化活性位点。这为基于原位SERS测量在原子水平上探索异质结构的催化机理的设计与合成铺平了道路。
