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.