Synthesis of Cu–Sb–S nanocrystals: insight into the mechanism of composition and crystal phase selection

Abstract

In this work, Cu–Sb–S nanocrystals (NCs) with various compositions and crystal structures are realized by only tuning the amount of 1-dodecanethiol (DDT). When the DDT amount is 3.6, 5.5, 20.5, and 25.6 mmol, pure tetragonal Cu₃SbS₄, cubic Cu₁₂Sb₄S₁₃, orthorhombic CuSbS₂, and orthorhombic Cu₃SbS₃ NCs are respectively obtained. Systematic investigations demonstrate that different amounts of DDT are responsible for formation of the different compositions and crystal structures of the initial Cu_2−xS seeds, which results into the formation of various Cu–Sb–S NCs. This reaction path is further verified by control experiments from successful preparation of Cu–Sb–S NCs comparable to that of the as-prepared ones directly from the reaction of Sb₂S₃ NCs with Cu_2−xS seeds. The current study not only provides a facile and economical way to synthesize high-quality Cu–Sb–S NCs, but also opens a new route for preparation other I–V–VI multicomponent chalcogenides NCs, such as Cu–Bi–S systems.