In-Situ Electrochemical Exfoliation and Methylation of Black Phosphorus into Functionalized Phosphorene Nanosheets

Two-dimensional black phosphorus (BP) has attracted great attention as a perspective material for various applications. The chemical functionalization of BP is an important pathway for the preparation of materials with improved stability and enhanced intrinsic electronic properties. Currently, most of the methods for BP functionalization with organic substrates require either the use of low-stable precursors of highly reactive intermediates or the use of difficult-to-manufacture and flammable BP intercalates. Herein we report a facile route for simultaneous electrochemical exfoliation and methylation of BP. Conducting the cathodic exfoliation of BP in the presence of iodomethane makes it possible to generate highly active methyl radicals, which readily react with the electrode's surface yielding the functionalized material. The covalent functionalization of BP nanosheets with the P-C bond formation has been proven by various microscopic and spectroscopic methods. The functionalization degree estimated by solid-state P-31 NMR spectroscopy analysis reached 9.7%.

Automated summary

Two-dimensional black phosphorus (BP) is a promising material for various applications, and its chemical functionalization is crucial for improving stability and enhancing intrinsic electronic properties. In this study, a facile method for simultaneous electrochemical exfoliation and methylation of BP was developed. The use of iodomethane during cathodic exfoliation allowed the generation of highly reactive methyl radicals, which reacted with the electrode's surface to yield functionalized BP nanosheets. The functionalization was confirmed by various microscopic and spectroscopic methods, with a degree of 9.7% estimated by solid-state P-31 NMR spectroscopy analysis.