Silver Ions Induce Lateral Etching of Gold Nanorods by K2PtCl4

Selective etching is significant for fabrication of novel nanostructures. Here silver ions are introduced to control the lateral etching of gold nanorods by K2PtCl4 in a hot solution, producing a number of dumbbell-like PtAu-Au thin gold nanorods. Silver ions control the selective deposition of the reduced Pt(0) atoms, causing the selective etching of the unprotected Au. The middle diameter of the obtained dumbbell-like nanorods can be adjusted from 12 nm to <10 nm. It is believed that this is an effective method to reduce the diameter of gold nanorods.