| Autor: |
Guan, Yanchao, Chen, Mengxin, Ding, Ye, Fang, Yuqiang, Huang, Fuqiang, Xu, Cheng-Yan, Zhen, Liang, Li, Yang, Yang, Lijun, Xu, Ping |
| Zdroj: |
ACS Nano; July 2024, Vol. 18 Issue: 26 p17339-17348, 10p |
| Abstrakt: |
In recent years, two-dimensional (2D) transition metal dichalcogenides (TMDCs) have been widely recognized as an ideal platform for surface-enhanced Raman scattering (SERS). Given their rich structural phases, phase transformation in 2D TMDCs is an efficient strategy to tailor their SERS performance. In this paper, we present the great SERS performance of multilayer 2M-WS2and then investigate the effect of its phase transformation on SERS performance. It is observed that multilayer 2M-WS2nanosheets undergo a thermally induced single-crystal phase transition from 2M-WS2to 2H-WS2upon thermal annealing or laser treatment. Distinguishing from the commercially available pure 2H-WS2(P-2H-WS2), 2H-WS2obtained by annealing and laser treatment still retain SERS properties comparable to those of 2M-WS2, among which the detection limits for CV molecules (10–8M) are 3 orders of magnitude lower than that of P-2H-WS2and the Raman intensity enhancements are ∼10–37 times higher. In contrast to the charge transfer (CT) mechanism governed by the Fermi level in metallic-phase 2M-WS2, 2H-WS2obtained by phase transition exhibits accelerated CT facilitated by the bandgap reduction and reorganization resulting from the abundance of vacancies. This study introduces an interesting perspective and potential avenue for enhancing SERS through metal-to-semiconductor phase transitions in 2D TMDCs materials. |
| Databáze: |
Supplemental Index |
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