Challenges and solutions in surface engineering and assembly of boron nitride nanosheets

Atomically thin boron nitride nanosheets (BNNSs) are normally considered to be chemically inert, which makes them difficult to be functionalized. Many applications require new surface functionalities. Significant efforts have been made towards surface engineering and assembly of BNNSs. In this article, we contribute a critical review of the topic on challenges and solutions in surface engineering and assembly of BNNSs. We first outline the mechanistic insights of tunable surface functionalization of BNNSs, and then highlight some new breakthroughs, seminal studies, and trends in the area that have been most recently reported by our groups and others. Recent application researches include but are not limited to: (1) chemical catalysis; (2) biocompatible BN functional nanomaterials for biological and biomedical applications; (3) molecularly engineered BN surfaces for sensing and drug delivery applications; and (4) the construction of thermally conductive and electrically insulating composites. There is also an in-depth discussion on the merits of the processing-structure–property relationships in the functionalized BNNSs. Finally, with this review article, we hope to spark new ideas and inspire new functionalization strategies by fundamentally understanding surface properties and engineering BNNSs with programmable structures and predictable properties.