Synthesis and characterization of chiral Ag2S and Ag2S–Zn nanocrystals

Abstract

This study focused on the synthesis of novel chiral Ag₂S and Ag₂S–Zn nanocrystals (NCs) with chiral Pen as a capping reagent in an aqueous solution. Luminescence studies indicated that all the prepared Ag₂S and Ag₂S–Zn NCs exhibited size-tunable photoluminescence (PL) emission at 500–700 nm. Compared with Ag₂S, the PL emission of the Ag₂S–Zn NCs could improve by around 2.4-fold. XRD peaks of the as-prepared Ag₂S NCs were weak, whereas the XRD peaks of the Ag₂S–Zn NCs had the characteristics of a monoclinic crystal structure. The circular dichroism (CD) test showed that the prepared NCs revealed a clear mirror-image relationship in their CD signals at 300–700 nm, and Zn²⁺ played a key role in the Cotton effect of the NCs. The chiral and fluorescent properties of these NCs are likely to find widespread applications in bioimaging, chemical and biosensing, and possibly in asymmetry catalysis.