Oxygen-Tailored MoS₂ as a High-Performance Substrate for Pressure-Induced Surface-Enhanced Raman Spectroscopy

Area of Science:

• Materials Science
• Spectroscopy
• Nanotechnology

Background:

• Pressure-induced surface-enhanced Raman spectroscopy (PI-SERS) is crucial for signal enhancement under extreme conditions.
• Effective PI-SERS implementation and mechanism elucidation are ongoing challenges.

Purpose of the Study:

• To develop novel oxygen-tailored MoS2 substrates for improved PI-SERS performance.
• To investigate the underlying mechanisms of PI-SERS enhancement.
• To explore SERS applications in high-pressure environments.

Main Methods:

• Fabrication of oxygen-incorporated MoS2 (MoS1.4O1.6) substrates.
• Detection of trace Rhodamine 6G (R6G) dye molecules.
• Density Functional Theory (DFT) calculations for mechanism analysis.
• High-pressure SERS measurements using MoO3 substrates.

Main Results:

• Oxygen-tailored MoS2 substrates achieved a detection limit of 10-7 M R6G and an enhancement factor (EF) of 1.53 × 10^6.
• DFT calculations confirmed significant intermolecular charge transfer (CT) contributing to Raman enhancement.
• MoO3 substrates showed pressure-dependent SERS performance, with an abrupt increase at 8.49 GPa due to resonant coupling.

Conclusions:

• Oxygen-tailored MoS2 significantly enhances PI-SERS performance and sensitivity.
• Intermolecular charge transfer is a key mechanism for PI-SERS enhancement.
• This study provides insights into high-pressure SERS mechanisms and applications.