Syntheses, Plasmonic Properties, and Catalytic Applications of Ag–Rh Core-Frame Nanocubes and Rh Nanoboxes with Highly Porous Walls

Abstract

We report a simple and general method for the production of Ag–Rh bimetallic nanostructures with a unique integration of the plasmonic and catalytic properties exemplified by these two metals, respectively. When a Rh(III) precursor is titrated into a polyol suspension of Ag nanocubes held at 110 °C in the presence of ascorbic acid and poly(vinylpyrrolidone), Rh atoms are generated and deposited on the nanocubes. When the amount of Rh(III) precursor is relatively low, the Rh atoms tend to nucleate from the edges of the Ag nanocubes and then follow an island growth mode because of the relatively low temperature involved and the high cohesive energy of Rh. The Rh islands can be maintained with an ultrafine size of only several nanometers, presenting an extremely large specific surface area for catalytic applications. As the amount of Rh(III) precursor is increased, the galvanic replacement reaction between the Rh(III) and Ag nanocubes will kick in, leading to the formation of increasingly concaved side faces...