Expressway to partially oxidized phosphorene

Abstract

Few-layer black phosphorus or phosphorene is an intriguing and important 2D material. It is a single-layer material that consists of corrugated and condensed six-membered phosphorus rings (Fig. 1). Each phosphorene layer can be weakly bonded to neighboring ones by van der Waals-like interactions to form few-layer arrangements, which are also called phosphorene in many publications. Finally, attaching many phosphorene layers to each other ends up as orthorhombic black phosphorus, a long-known phosphorus allotrope. There are two different few-layer 2D materials of phosphorus known to date, which can be derived from the element structures of orthorhombic black phosphorus (1) or gray arsenic (2). The latter is discussed as blue phosphorus in the literature (3). Since 2014, when few-layer black phosphorus was first prepared by a top-down approach from black phosphorus and used as field effect transistors (4⇓–6), a continuously increasing interest can be observed for this 2D material. Recently, an elegant, well-defined, and controllable bottom-up route for partially oxidized phosphorene ( po- phosphorene) was reported (7). In a one-pot and also low-cost process, molecular highly reactive white phosphorus acts as starting material and ethylene diamine serves as a solvent and reaction promotor (4). In a low-temperature reaction at 100 °C, po- phosphorene can be achieved on a gram scale. Due to traces of oxygen present in the solvent or during the synthesis process, the target material is partially oxidized on the surface. This aspect may look like a disadvantage at first glance, but it has turned out to be beneficial for the long-term air and moisture stability of the final product. The report in PNAS by Tian et al. (7) on the first bottom-up synthesis of well-defined po -phosphorene is a major breakthrough in synthetic chemistry. It paves the way for the large-scale … [↵][1]1Email: tom.nilges{at}lrz.tum.de. [1]: #xref-corresp-1-1