Analogous self-assembly and crystallization: a chloride-directed orientated self-assembly of Cu nanoclusters and subsequent growth of Cu _2−x S nanocrystals

Self-assembly and crystallization are two common methods to control the morphologies of nanomaterials, which have many similarities. In this work, chloride is used to direct the self-assembly process of Cu nanoclusters and the subsequent growth of Cu_2-xS nanocrystals. Meaningfully, chloride both promotes the transformation of Cu nanocluster self-assembled architectures from one-dimensional (1D) to 2D, and facilitates the transformation of Cu_2-xS nanocrystals from nanorods to nanosheets. Such an influence is attributed to the selective adsorption of chloride ions on the specific facets of nanoclusters and nanocrystals, which alters the inter-nanocluster weak interactions during self-assembly and suppresses the activity of Cu_2-xS facets during nanocrystal growth. The current results indicate that the method used to direct the morphologies of nanocrystals is extendable to control the tendency of nanocluster self-assembly.