Rhodium growth on Cu₂S nanocrystals yielding hybrid nanoscale inorganic cages and their synergistic properties

Metal decoration on the edges of highly faceted Cu₂S semiconductor nanocrystals yields a family of nano-inorganic caged (NICed) hybrid semiconductor-metal nanoparticles. We present the growth of rhodium and of ruthenium-rhodium mixture to give Rh-Cu₂S and RuRh-Cu₂S hybrid nanoparticle cages, respectively. Transmission electron microscopy affirms the growth of the metals selectively on the nanocrystal edges within a narrow temperature window. The oxidation level of the metal frame could also be controlled during the reaction stages as characterized by X-ray photoelectron spectroscopy, providing additional variation for the hybrid nanoparticle cages. The synergistic electronic properties of the hybrid nanocages were observed on a single particle level using scanning tunneling spectroscopy. The various cage nanoparticles are also of interest as possible catalysts for metal and metal-oxide catalyzed reactions.