The Design of WTe 2 /Graphene/Ag NPs Heterostructure for the Improvement of the Chemical Enhancement in SERS

作者：Tianyu Sun, Yang Wu, Heqi Ma, Chao Zhang, Chonghui Li, Baoyuan Man, Cheng Yang, Zhen Li · 发表于：Nano Letters · 年份：2024 · DOI：10.1021/acs.nanolett.4c04339 · 被引用次数：31 · 研究领域：Gold and Silver Nanoparticles Synthesis and Applications、2D Materials and Applications、Quantum Dots Synthesis And Properties

Combining the advantages of metal and two-dimensional (2D) nanomaterials, various 2D/metal composite structures are proposed as surface-enhanced Raman spectroscopy (SERS) substrates. However, the chemical enhancement in the composite structure is usually less responsible for the total enhancement. In this work, we proposed a heterostructure including WTe 2 /graphene/Ag nanoparticles (WTe 2 /Gr/Ag) as an effective platform for SERS. The matching of energy levels facilitates charge transfer (CT) within the composite structure, which in turn significantly improves the chemical enhancement of SERS. Compared with WTe 2 /Ag or Gr/Ag substrate, the SERS signals can be amplified up to 18-fold, and the detection limit could further reduce 3 orders of magnitude. Furthermore, the CT process in the SERS test can be further promoted after introducing the pyroelectric field based on the ferro-electricity of WTe 2 . The enhancement factor of the WTe 2 /Gr/Ag substrate finally reached 1.34 × 10 12 . This work proposes a new idea for the design of highly sensitive SERS sensors.