Revisiting the Growth of Black Phosphorus in Sn-I Assisted Reactions

• Main Authors: Dongya Wang, Peng Yi, Lin Wang, Lu Zhang, Hai Li, Min Lu, Xiaoji Xie, Ling Huang, Wei Huang
• Format: Article
• Language: English
• Published: Frontiers Media S.A. 2019-01-01
• Series: Frontiers in Chemistry
• Subjects: black phosphorus; growth mechanism; tin iodide; chemical vapor transport; 2D materials
• Online Access: https://www.frontiersin.org/article/10.3389/fchem.2019.00021/full

Black phosphorus, an emerging layered material, exhibits promising applications in diverse fields, ranging from electronics to optics. However, controlled synthesis of black phosphorus, particularly its few-layered counterparts, is still challenging, which should be due to the unclear growth mechanism of black phosphorus. Here, taking the most commonly used Sn-I assisted synthesis of black phosphorus as an example, we propose a growth mechanism of black phosphorus crystals by monitoring the reactions and analyzing the as-synthesized products. In the proposed mechanism, Sn24P19.3I8 is the active site for the growth of black phosphorus, and the black phosphorus crystals are formed with the assistance of SnI2, following a polymerization-like process. In addition, we suggest that all Sn-I assisted synthesis of black phosphorus should share the same reaction mechanism despite the differences among Sn-I containing additives. Our results shown here should shed light on the controlled synthesis of black phosphorus and facilitate further applications of black phosphorus.