Keggin ions as UV-switchable reducing agents in the synthesis of Au core-Ag shell nanoparticles.
Keggin ion-mediated synthesis of Au core-Ag shell bimetallic nanoparticles is described. Exposure of photochemically reduced aqueous (PW12O40)3- Keggin ions to AuCl4- ions leads to the formation of stable gold nanoparticles capped by the Keggin ions. The surface-bound Keggin ions may then be activated by UV irradiation and, upon exposure to Ag+ ions, reduce the metal ions to form a silver shell around the gold core. That the capping agent not only stabilizes the metal nanoparticles but also plays the role of a switchable reducing agent is a highlight of this approach with important implications in nanomaterials synthesis and catalysis.
Mandal
Saikat
S
Materials Chemistry Division, National Chemical Laboratory, Pune-411 008, India.
Selvakannan
P R
PR
Pasricha
Renu
R
Sastry
Murali
M