Ripening of Gold Clusters into a Single Domain on Semiconductor Quantum Rods during Langmuir–Blodgett Deposition

Rapidly forming, large gold nanocrystals (∼10 nm) on CdSe/CdS nanorods while maintaining the nanorod geometry remains challenging. In this study, we demonstrate that by using Langmuir–Blodgett (LB) deposition, numerous tiny gold nanocrystals (2–3 nm) can ripen into a single gold nanocrystal with a size of 8–9 nm on each nanorod within 4 h. Thanks to the room temperature condition and low corrosiveness of the chemicals used in the technique, the nanorod geometry was perfectly maintained. Besides, the reaction was found to be accompanied by a ligand exchange procedure, which perhaps resulted in a hydrophobic/hydrophilic “Janus” structure on the final hybrid nanoparticles.