Ab Initio Prediction of Catalytic Elemental Metals for Black Phosphorus Synthesis from Investigations of Interactions among the Elemental Metals, Iodine, and Phosphorus Clusters

The unique structural and electronic properties of black phosphorus (BP) have motivated intensive research on the synthesis of large-scale and high-quality BP films at atmospheric pressure. To date, only Sn and I2 have been found to be the essential materials for the successful growth of BP crystals using the chemical vapor transport method. However, the Sn-based growth process is highly expensive because of the slow growth rate and separation of the byproduct from BP and depends on the interaction among Sn, I, and P. In this work, using ab initio density functional theory calculations, we have examined the growth of BP on Ag, Au, Cu, In, Cd, Sn, Pb, Sb, Te, and Bi metal particles to understand the origin of the unique catalytic performance of Sn and Te, suggesting possible avenues for obtaining improved catalysts. Our results show that Ag, Au, Cu, In, Cd, and Sb show strong interactions with P that make them unsuitable for BP catalysis, while Sn, Pb, Te, and Bi show weak interactions with P that in principle can enable P4 polymerization and the growth of BP and red phosphorus (RP) on these metals. However, in the absence of I, RP growth is preferred for all metals. In the presence of I and P, strong metal-I bonds are observed for Pb and Bi; such bonds are likely to disfavor the BP catalytic growth on Pb and Bi, in agreement with experimental findings. Based on their metal-P and metal-I interactions, Sn and Te are identified as good catalysts for BP synthesis. Therefore, we suggest that Te and its alloys should be investigated as BP synthesis catalysts.