Copper-Ion-Assisted Precipitation Etching Method for the Luminescent Enhanced Assembling of Sulfur Quantum Dots.

In this study, we report a metal-ion-assisted precipitation etching strategy that can be used to manipulate the optical properties associated with the assembling of sulfur quantum dots (S dots) using copper ions. Transmission electron microscopy confirmed that the S dots were mainly distributed within 50-80 nm and that they exhibited an ambiguous boundary. After the post-synthetic Cu-assisted modification was completed, the assisted precipitation-etching S dots (APE-S dots) were observed to exhibit a relatively clear boundary with a high fluorescence (FL) quantum yield (QY) of 32.