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

A quadrupole electric field-mediated exfoliation method is proposed to convert micron-sized hexagonal boron nitride (h-BN) powder into few-layer hexagonal boron nitride nanosheets (h-BNNS). Under optimum conditions (400 Hz, 40 V, 32 μg ml−1, sodium deoxycholate, TAE medium), the h-BN powders (thickness >200 nm, horizontal scale ~10 μm) are successfully exfoliated into 0.5–4 nm (1–10 layers) thick h-BNNS with the same horizontal scale. Dynamic laser scattering and atomic force microscope data show that the yield is 47.6% (for the portion with the thickness of 0.5–6 nm), and all of the vertical sizes are reduced to smaller than 18 nm (45 layers).