Environment-friendly, scalable exfoliation for few-layered hexagonal boron nitride nanosheets (BNNSs) by multi-times thermal expansion based on releasing gases
The environment-friendly but facile scalable exfoliation route for two-dimensional hexagonal boron nitride (h-BN) was impetus for potential applications. In this work, we invented a competitive exfoliation route for high-yield BNNSs on the basis of the above targets. By means of the releasing gases derived from the decomposition of oxalic acid pre-impregnated in the interlayers of bulk h-BN, the scalable exfoliation was achieved by multi-times thermal expansion. The as-exfoliated BNNSs with intact inplane structure had a 3-5 nm thickness and approximately 13.6% output. Furthermore, the high-quality BNNSs exhibited a better dispersion in base oil, which was conductive to be applied as additive in oil because of superlubricity properties of two-dimensional layered nanosheets.