Zhang Chao, Ji Chang, Yu Jing, Li Zhen, Li Zhaoxiang, Li Chonghui, Xu Shicai, Li Weifeng, Man Baoyuan, Zhao Xiaofei
Opt Express. 2021 Nov 8;29(23):38768-38780. doi: 10.1364/OE.441176.
MoS-based heterostructures have received increasing attention for not only surface-enhanced Raman scattering (SERS) but also for enhanced photoelectrocatalytic (PEC) performance. This study presents a hydrothermal method for preparing vertical MoS nanosheets composed of in situ grown AuNPs with small size and chemically reduced AgNPs with large size to achieve the synergistic enhancement of SERS and PEC properties owing to the size effect of the plasmonic structure. Compared with pristine MoS nanosheets and unitary AuNPs or AgNPs composited with MoS nanosheets, the ternary heterostructure exhibited the strongest electromagnetic field and surface plasmon coupling, which was confirmed by finite-difference time-domain (FDTD) simulation and absorption spectra. In addition, the experimental results confirmed the outstanding SERS enhancement with an EF of 1.1×10, and the most efficient hydrogen evolution reaction (HER) activity with a sensitive photocurrent response, attributing to the multiple surface plasmonic coupling effects of the Au-Ag bimetal and efficient charge-transfer process between MoS and the bimetal. That is, it provides a robust method for developing multi-size bimetal-semiconductor complex nanocomposites for high-performance SERS sensors and PEC applications.
基于MoS的异质结构不仅因其表面增强拉曼散射（SERS），还因其增强的光电催化（PEC）性能而受到越来越多的关注。本研究提出了一种水热法，用于制备由原位生长的小尺寸AuNPs和化学还原的大尺寸AgNPs组成的垂直MoS纳米片，以实现由于等离子体结构的尺寸效应而对SERS和PEC性能的协同增强。与原始MoS纳米片以及与MoS纳米片复合的单一AuNPs或AgNPs相比，三元异质结构表现出最强的电磁场和表面等离子体耦合，这通过有限时域差分（FDTD）模拟和吸收光谱得到了证实。此外，实验结果证实了其具有1.1×10的增强因子（EF）的出色SERS增强效果，以及具有灵敏光电流响应的最有效的析氢反应（HER）活性，这归因于Au-Ag双金属的多重表面等离子体耦合效应以及MoS与双金属之间有效的电荷转移过程。也就是说，它为开发用于高性能SERS传感器和PEC应用的多尺寸双金属-半导体复合纳米复合材料提供了一种可靠的方法。
