Scalable Exfoliation and High‐Efficiency Separation Membrane of Boron Nitride Nanosheets

Abstract Hexagonal boron nitride nanosheets (h‐BNNSs) refer to a class of two‐dimensional materials with promising applications. However, the current method of exfoliating hexagonal boron nitride (h‐BN) into h‐BNNS limits its large‐scale application. Herein, a method was developed to exfoliate h‐BN through sucrose assisted discontinuous, multiple ball milling. A series of defect‐free, ultra‐thin large lateral‐size h‐BNNSs were successfully obtained, with a yield as high as 85 wt %. Finally, the membranes of BNNS obtained by vacuum filtration displayed a good separation performance in different organic pigment solutions. The separation rates of BNNS‐20 membranes for methylene blue and Congo red reached 87 % and 95 %, respectively. The results show that the functionalized h‐BNNSs obtained by sucrose‐assisted discontinuation, multiple ball milling have good stability in water, and hence can be applied to wastewater treatment.