Chemical-free exfoliation of hexagonal boron nitride via cavitation-bubble plasma in water

Hexagonal boron nitride (h-BN) sheets have numerous applications, but current low-cost, environmentally friendly techniques for h-BN exfoliation yield undesirably small sheet sizes. We have developed a novel chemical-free method to prepare large h-BN nanosheets (BNNSs) by the exfoliation of h-BN using plasma with cavitation bubbles in water, named here as cavitation-bubble plasma. Unlike ordinary liquid exfoliation methods, which reduce the sheet size of BNNSs compared with that of the starting h-BN, the cavitation-bubble plasma process exfoliated h-BN without reducing the sheet size. Furthermore, the plasma dramatically improved the exfoliation yield.