Two-dimensional MBenes with ordered metal vacancies for surface-enhanced Raman scattering

Area of Science:

• Materials Science
• Nanotechnology
• Analytical Chemistry

Background:

• Two-dimensional (2D) materials, specifically MBenes, are emerging with significant potential for optoelectronic applications.
• The utility of MBenes as surface-enhanced Raman scattering (SERS)-active materials for molecular sensing remains unexplored.

Purpose of the Study:

• To develop a novel, high-performance MBene-based SERS platform for sensitive molecular detection.
• To investigate the SERS activity and mechanism of a 2D Mo4/3B2 MBene material.

Main Methods:

• Design and synthesis of a 2D Mo4/3B2 MBene material with ordered vacancies.
• Characterization of SERS activity, including Raman enhancement factor and detection limits.
• Systematic experimental studies and density functional theory (DFT) calculations to elucidate the SERS mechanism.

Main Results:

• A 2D Mo4/3B2 MBene SERS platform exhibiting superior activity compared to most semiconductor substrates was developed.
• Remarkable Raman enhancement factor of 3.88 × 10^6 and an ultralow detection limit of 1 × 10^-9 M were achieved.
• Ordered metal vacancies in the 2D Mo4/3B2 MBene led to uniform charge transfer sites, resulting in outstanding signal uniformity (RSD down to 6.0%).

Conclusions:

• The 2D Mo4/3B2 MBene material demonstrates ultrahigh SERS sensitivity attributed to efficient photoinduced charge transfer.
• The abundant electronic density of states near the Fermi level of 2D Mo4/3B2 MBene significantly enhances Raman signals.
• This work establishes MBenes as a promising class of materials for advanced SERS-based chemical sensing platforms.