We studied the chemical, optical and catalytic properties of metal (Pt, Pd, Ag, Au)-Cu 2 O core-shell nanoparticles grown via a simple and reproducible approach which utilizes aqueous-phase reactions at room temperature. We were able to control the thickness of the Cu 2 O shell and examine the effect of the core's shape and size on the structure and properties of the hybrid nanocrystals. We also studied the optical properties of the hybrid nanocrystals, in particular the effect of the Cu 2 O shell thickness on the frequency of the plasmon of gold nanorods. In addition, the catalytic activity of the hybrid nanostructures was examined by testing the reduction reaction of 4-nitrophenol with NaBH 4 . Finally, the hybrid metal-Cu 2 O nanostructures were used as templates to form the yolk-shell of metal-Cu 2 S materials. The interface and the crystalline structures of the four hybrid nanostructures were extensively characterized by high resolution transmission electron microscopy (HRTEM), energy-filtered TEM (EFTRM) and X-ray diffraction (XRD).

Multi-component nanostructures of Au-CdS-ZnO with a novel morphology were synthesized by a non-conventional strategy where seeded growth is combined with solution-liquid-solid (SLS) growth. Each of these synthetic routes is used for growing a different domain of the final heterostructure, where ZnO rods are grown first on Au nanoparticles via heterogeneous nucleation while CdS is later grown between these two domains via SLS, using the Au tip of the preformed Au-ZnO as a catalyst. The in situ alloying of the Au tip with Cd enabled the metal tip to function as an SLS catalyst at a relatively mild reaction temperature which is lower than the melting point of pure Au.

Hybrid nanostructures of metal (Cu, Au, Ag)-ZnO nanopyramids were synthesized. These hybrid nanostructures possess two distinct morphologies where the metal can be selectively attached to either the base or the tip of the ZnO pyramids. This is the first time that such morphologies are reported for Cu-ZnO and Ag-ZnO hybrid nanostructures.

We demonstrate a general approach for growing selectively semiconductor nanocrystals onto the edges of elongated Cdchalcogenide nanostructures. Our approach utilizes the thermal decomposition of metal bisdiethyldithiocarbamate precursors to achieve selective growth onto cadmium chalcogenide nanostructures.