Mechanistic Investigation of Cation Exchange in 3D Superlattice

The retention of the dimensionality of superlattices (SLs) through cation exchange has posed innumerable challenges within the domain of materials science. To date, no synthetic protocol has been developed for the conservation of superlattice dimensionality through a cation exchange approach. In this letter, we have retained the dimensional integrity of Cu_1.8S nanorod SLs during the transmutation to Ag₂S and CdS nanorod SLs through a cation exchange process with Ag⁺ or Cd²⁺ ions. Moreover, the growth mechanism governing the cation exchange and the packing pattern of the nanocrystals in Ag₂S and CdS nanorod SLs have been elucidated through the small-angle X-ray scattering (SAXS) technique. The synthesized nanorod SLs displayed high stability, with no observable disassembly in solvents (hexane, toluene, and ethanol) for a month. The Ag₂S and CdS SLs acquired from Cu_1.8S SLs via cation exchange have potential applications in high-performance electronic and optoelectronic devices.