Large-area few-layer hexagonal boron nitride prepared by quadrupole field aided exfoliation

Area of Science:

• Materials Science
• Nanotechnology
• Physical Chemistry

Background:

• Hexagonal boron nitride (h-BN) is a 2D material with unique thermal and electrical properties.
• Exfoliation of bulk h-BN into few-layer nanosheets is crucial for its applications.
• Existing methods often struggle with scalability and achieving desired layer counts.

Purpose of the Study:

• To develop an efficient method for producing few-layer hexagonal boron nitride nanosheets (h-BNNS) from bulk h-BN powder.
• To optimize exfoliation parameters for high yield and controlled thickness.
• To characterize the resulting h-BNNS.

Main Methods:

• Utilized a quadrupole electric field-mediated exfoliation technique.
• Optimized parameters including frequency (400 Hz), voltage (40 V), concentration (32 μg ml⁻¹), surfactant (sodium deoxycholate), and medium (TAE).
• Characterized exfoliated products using dynamic laser scattering and atomic force microscopy.

Main Results:

• Successfully converted micron-sized h-BN powder (thickness >200 nm) into few-layer h-BNNS (0.5-4 nm thickness, 1-10 layers).
• Achieved a yield of 47.6% for h-BNNS with thickness between 0.5-6 nm.
• Reduced the vertical size of all exfoliated materials to below 18 nm (45 layers).

Conclusions:

• The quadrupole electric field method is effective for producing high-quality h-BNNS.
• Optimized conditions enable controlled exfoliation of h-BN powder into few-layer nanosheets.
• This technique offers a promising route for scalable production of h-BNNS for various applications.