Nonconductive layered hexagonal boron nitride exfoliation by bipolar electrochemistry
Boron nitride (h-BN), which is an isoelectronic analogue of graphite, has received immense attention due to its unique physical and chemical properties. Numerous methods have been developed to isolate few-layered h-BN nanosheets. These include chemical vapour deposition, solution-based exfoliation and ball-milling amongst others. The bipolar electrochemical method is one of the popular, scalable and water based exfoliation methods which has been applied to graphite, layered transition metal dichalcogenides and black phosphorus. This method was not applied to insulators as this has been assumed to be an impossible task. In this study, we report a solution-based, scalable and time efficient bipolar electrochemical method for the direct exfoliation of bulk insulator, layered h-BN into few-layered h-BN nanosheets based on bipolar electrochemistry. The electrochemical exfoliation of nonconductive materials, h-BN, opens the way to the application of this scalable method to the whole spectrum of non-conductive layered materials. This facile method offers an alternative platform for h-BN electrochemical exfoliation in wide-ranging fields encompassing electronics and biomedical science.