Black Phosphorus Synthesis Path Strongly Influences Its Delamination, Chemical Properties and Electrochemical Performance

We show here that synthetic approaches to layered black phosphorus (BP), namely, high-pressure conversion of red phosphorus (RP) and vapor growth of BP from RP in the presence of Sn/SnI4, lead to dramatically different crystallinity of BP which in turn strongly influences its exfoliation, chemical and electrochemical properties. In particular, we demonstrate that black phosphorus (BP) shear exfoliation in aqueous surfactant media can be used to obtain well-defined and few-layer BP nanosheets and that this depends on the crystallinity of BP. The process can proceed without the need to use glovebox or purging solutions. BP consisting of large well-developed crystals obtained by vapor growth methods and containing trace amounts of Sn is easily exfoliated. On other hand, highly pure nanocrystalline BP obtained by the high-pressure method could not be extensively exfoliated by shear mixing. Starting material BP crystallinity furthermore influences its counterpart shear exfoliated BP surface chemistry and electrochemical performance.