Crystalline‐Amorphous Heterostructure: A Novel Configuration for Silver Nanoclusters

Abstract Heterostructured composite materials with multiple components have potential applications in diverse aspects, as they tend to exhibit superior physicochemical properties than the sum of their single counterparts. However, the fabrication of heterostructures composed of atomic‐precise metal nanoclusters (NCs) is seldom reported owing to their inherent instability, leading to the decomposition of metal NCs during the formation of peripheral layers. Here, a spontaneously formed amorphous‐crystalline heterostructured Ag 40 @Ag 12 is discovered, wherein the amorphous Ag 40 NCs are enveloped by a single crystal of Ag 12 NCs. The formation of Ag 40 @Ag 12 involves three stages, including initial crystallization of Ag 40 NCs, partial decomposition (self‐sacrifice) of Ag 40 NCs enabling Ag 12 assembly, and epitaxial‐growth crystallization of the Ag 12 NCs. The partially decomposed Ag 40 NCs provide starting materials for the formation and crystallization of Ag 12 NCs to encapsulate the Ag 40 seeds, while the residual Ag 40 loses its crystallinity in solution simultaneously. This work not only reports a novel class of heterostructured materials for the first time but also provides new insights into the macroscopic co‐assembly of distinct silver clusters.