Platinum Overgrowth on Gold Multipod Nanoparticles: Investigation of Synergistic Catalytic Effects in a Bimetallic Nanosystem

Abstract Highly ordered heteronanostructures can be synthesized by overgrowth of a secondary material on the as‐prepared seed nanocrystal. The unique morphology of seed nanocrystals directs the shape of the secondary structure, which is exploited to develop structure‐controlled composite nanomaterials. Herein, we report a facile and controllable synthetic strategy toward noble star‐shaped bimetallic nanostructures. Gold multipod nanoparticle (GMN) core–platinum shell nanoparticles (GMN@Pt NPs) are successfully synthesized through the overgrowth of Pt on the surface of GMN seeds. Due to the structural uniqueness of GMNs, GMN@Pt NPs show bimetallic core–shell geometries, which have surface roughness and star‐shaped multi‐branches with sharp edges and tips. The island nucleation and growth of individual Pt particles to form a shell provide larger surface areas and plenty of defects on the bimetallic nanocrystals. GMN@Pt NPs with optimized Pt shells show much higher catalytic activities in 4‐nitrophenol reduction and ethanol electrooxidation than those of GMNs or Pt nanoparticles, mainly due to the synergistic effects of the bicomponent nanosystem.