Ultraviolet-ozone concomitantly induced MoS₂/MoO heterostructures with improved SERS performance.

Area of Science:

• Materials Science
• Spectroscopy
• Nanotechnology

Background:

• Surface-enhanced Raman scattering (SERS) offers high sensitivity for detecting trace molecules.
• Transition metal oxides/chalcogenides are cost-effective SERS substrates but have limited enhancement.
• Noble metals are effective SERS substrates but are expensive.

Purpose of the Study:

• To develop a novel SERS substrate with significantly improved performance.
• To investigate MoS₂/MoO heterostructures as a promising alternative to noble metal SERS substrates.
• To elucidate the mechanism behind the enhanced SERS performance.

Main Methods:

• Fabrication of MoS₂/MoO heterostructures via controlled oxidation of MoS₂ nanospheres using ultraviolet-ozone.
• Optimization of SERS substrate performance through precise control of oxidation time.
• Characterization of SERS performance using rhodamine 6G (R6G) as a probe molecule.

Main Results:

• Optimized MoS₂/MoO heterostructures achieved a detection limit of 10^-7 M for R6G.
• An exceptional enhancement factor of 7.477 × 10⁶ was recorded for R6G at 10^-7 M.
• Energy band analysis revealed enhanced electron-hole separation and charge transfer contributing to improved SERS.

Conclusions:

• MoS₂/MoO heterostructures demonstrate superior SERS performance compared to traditional materials.
• The enhanced electron-hole separation and charge transfer mechanism are key to improved SERS activity.
• This work presents a viable, low-cost alternative for sensitive trace molecule detection using SERS.