Cu2 S/ZnS Heterostructured Nanorods: Cation Exchange vs. Solution-Liquid-Solid-like Growth

Abstract

Cu2 S/ZnS heterostructured nanorods (HNRs) with uncommon morphologies are achieved through single-pot and multi-batch synthetic strategies. In both cases, Cu2 S NRs form first, which then undergo partial cation exchange and solution-liquid-solid (SLS)-like growth catalyzed by the remaining Cu2 S parts of the NRs. The location and the volume of ZnS achieved through partial cation exchange control the size of the Cu2 S catalysts, which in turn determine whether tapered rod-rod, body/tail, or barbell-like structure results from subsequent SLS-like growth. Concurrent cation exchange can sometimes cause Cu2 S catalysts to be lost during SLS-like growth, leading to further diversity in achievable morphologies of Cu2 S/ZnS HNRs. Additional insights are gained on how parameters such as Zn precursor, ligand choice, and concentration alter cation exchange and SLS-like growth steps.

Keywords: cation exchange; nanostructures; precursor chemistry; reaction mechanisms; solution-liquid-solid-like growth.