High-yield synthesis of extremely high concentrated and few-layered boron nitride nanosheet dispersions

Due to the strong 'lip–lip' interactions between neighboring nanosheets layers, the scalable exfoliated fabrication of few-layer-thick boron nitride nanosheets (BNNSs) from the bulk hexagonal boron nitride (h-BN) is more challenging than these graphene nanosheets. In this work, few-layer (generally less than 10 layers) BNNSs were efficiently synthesized through a simple ball milling technique with the 2-furoic acid (FA) as a modifier. The BNNSs as-prepared with a average thickness of about 2.0 nm and an extremely high production yield (~98%) as well as unprecedentedly high dispersed concentration (~35 mg ml−1) in water. The stable aqueous dispersions of BNNSs can be directly used to fabricate ultralight aerogels with a low density of 2.0 mg cm−3 and thermally conductive film with a highly thermal conductivity of 25.2 W m−1 K−1. This approach provided us with an environmentally friendly agent with high efficiency for few-layer BNNSs synthesis and demonstrated promising applications for ultralight aerogels and heat dissipation in electronic components.