Exfoliation of MoS₂ and h-BN nanosheets by hydrolysis of LiBH₄

Abstract

Efficient preparation of two-dimensional materials is still a great challenge. These materials possess unique electrical, optical, and thermal properties. In this study, few-layer MoS₂ nanosheets and nanoflakes were exfoliated by the hydrolysis reaction of LiBH₄. First, the layered MoS₂ powder materials were mixed with LiBH₄ to obtain a homogeneous powder mixture, and then the mixture was heated above the melting point of LiBH₄ under 300 °C and 4 MPa H₂ for 2 h, during which the layered materials were curled by liquid LiBH₄. In the subsequent hydrolysis of LiBH₄, the layered materials were split into nanosheets by H₂ gas generation. The obtained MoS₂ nanosheets show almost uniform thickness of ~4 nm, with a width of 2-10 μm and a yield of more than 1.5 wt.%. The effectiveness of this method has also been verified by the preparation of few-layer h-BN. This work provides a new high-yield route to producing two-dimensional materials.