title: Keggin ions as UV-switchable reducing agents in the synthesis of Au core-Ag shell nanoparticles.
abstract: 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.
authors.affiliation: Materials Chemistry Division, National Chemical Laboratory, Pune-411 008, India.
authors.forename: Saikat
authors.initials: S
authors.lastname: Mandal
authors.forename: P R
authors.initials: PR
authors.lastname: Selvakannan
authors.forename: Renu
authors.initials: R
authors.lastname: Pasricha
authors.forename: Murali
authors.initials: M
authors.lastname: Sastry