Facile and Efficient Preparation of High-Purity Black Phosphorus Based on a Vapor-Solid-Vapor Phase Growth Mechanism

Black phosphorus (BP), a promising layered material widely used in energy storage systems, sensors, and transistors, is usually prepared by mineralization. However, without a clear BP growth mechanism, various problems arise, such as a high preparation cost, low preparation efficiency, and poor purity; the insufficient information concerning the BP growth mechanism greatly limits the large-scale application of this material. Therefore, it is imperative to develop an efficient preparation method and to improve the purity of BP. In this work, the BP growth mechanism was explored. The catalytic role of Sn24P19.3I8 was determined. Furthermore, a vapor-solid-vapor (VSV) phase BP growth mechanism was proposed. Based on the proposed growth mechanism, BP crystals can be prepared efficiently with high purity. Moreover, the Sn24P19.3I8 catalyst preparation procedure was optimized, which largely improved its preparation efficiency. The research results lay a foundation for the large-scale, low-cost, and continuous preparation of BP.