Highly Efficient Mass Production of Boron Nitride Nanosheets via a Borate Nitridation Method

Boron nitride nanosheets (BNNSs) have attracted intensive attention because of their fantastic properties, including excellent electrical insulating ability, splendid thermal conductivity, and outstanding oxidation resistance. However, facing the rising demand for versatile applications, the cost-effective mass production of BNNSs, similar to graphene, remains a huge challenge. Here, we provide a highly effective strategy for BNNS synthesis via a borate nitridation method utilizing solid borate precursors, producing gram-scale yields with efficiencies up to 88%. Combined with density functional theory (DFT) calculations, a vapor-solid-solid (VSS) mechanism was proposed in which ammonia vapor reacts with the solid borates, producing solid BNNSs at the vapor-solid interfaces. The strategy proposed herein, together with the diversity of borate compounds, allows numerous choices for the facile mass production of BNNSs at low cost. In addition, the remarkably enhanced thermal conductivity in composite materials demonstrated good quality and huge potential for these BNNSs in thermal management. This work reveals a cost-efficient method for the large-scale production of BNNSs, which should promote practical applications in various fields.