Core@shell sub-ten-nanometer noble metal nanoparticles with a controllable thin Pt shell and their catalytic activity towards oxygen reduction

Reducing Pt loading, while improving electrocatalytic activity and the stability of Pt-based nanostructured materials, is currently a key challenge in green energy technology. Herein, we report the controllable synthesis of tri-metallic (Au@Ag@Pt) and bimetallic (Ag@Pt) particles consisting of a controllable thin Pt shell, via interface-mediated galvanic displacement. Through oil-ethanol-H₂O interface mediation, the controllable “out to in” displacement of Ag atoms to Pt enables the formation of a thin Pt shell on monodisperse sub-ten-nanometer Au@Ag and Ag nanocrystals. The synthesized nanoparticles with a thin Pt shell exhibited potential catalytic activity towards the oxygen reduction reaction (ORR) due to the high exposure of Pt atoms.