Electrochemical cathode exfoliation of bulky black phosphorus into few-layer phosphorene nanosheets

Black phosphorus (BP) has gained great interest due to its tunable band-gap structure which strongly depends on the number of layers. The key step therefore towards application of BP is the preparation of few-layer or multilayer BP materials. However, because of the high chemical reactivity of BP, the preparation process must be handled with special care to avoid oxidation-induced degradation. Here we introduced a facile and scalable electrochemical method to generate BP nanosheets where BP served as the cathode. Subsequently, the product was characterized by TEM, Raman, UV-Vis, AFM, XPS and FTIR techniques. The relevant characterization data indicated that the thickness of the obtained BP nanosheets was mainly in the range of 2-7 nm. Furthermore, oxidation can be completely avoided during this electrochemical cathode exfoliation process, which provided high-quality BP nanosheets.