Stable One-Dimensional Single Crystalline Black Phosphorus Nanowires for Gas Sensing

Layered black phosphorus (BP), as a well-known type of two-dimensional (2D) material, has exhibited many fascinating properties in the fields of electronics, photonics, and chemical applications. However, the instability of 2D phosphorus is the primary obstruction toward practical applications, and the properties of one-dimensional (1D) black phosphorus remain unexplored. Here, we have first successfully synthesized 1D single crystalline BP nanowires, which represent the characteristics of good stability, narrow width (&tild;100 nm), wafer-scale arrays, and high surface to volume ratio. The used melting-injection-transformation method at high pressure with red phosphorus being the starting material is inexpensive, controllable, and productive. The unique superiorities of BP nanowires thus enable a one-step fabrication of BP gas sensors with fast response, long operating life, and strong robustness. This work opens a dimension to explore the properties of BP and also provides a 1D structure engineering strategy toward an efficient large-scale fabrication, endowing traditional materials with fresh attributes for practical applications.