We report the synthesis of PVP-capped Au-CdSe hybrid nanostructures synthesized using the UV-irradiation method. The high resolution transmission electron microscopy (HRTEM) and powder X-ray diffraction (XRD) studies confirm the presence of the hybrid gold and CdSe nanoparticles. 1. Introduction Metals and semiconductor nanomaterials with diverse morphologies such as rods [1, 2], tetrapods [3], prisms [4], cubes [5], and other complex shapes [6, 7] have been regularly reported in nanoscience literature. However, the synthesis of multicomponent materials incorporating a metal and a semiconductor material is not very common. Such systems represent a new class of materials, where catalytic metals are paired with a semiconductor material within the same structure. This combination of a metal-semiconductor material provides new functionalities to the nanostructures. They have been studied as photocatalysts, in photoelectrochemical cells, in the photochemical purification of organic contaminants, and in bacterial detoxification [8]. The excitation of the surface plasmon in metal nanoparticles placed into a semiconductor can be expected to enhance optical properties such as absorption and photoluminescence. Heterostructured materials such as Au-CdSe [9], Au-CdS [9], Au or Ag on ZnO [10], Co and Au on TiO2 and PbS/Au nanowires have been reported [11]. In order to successfully synthesize multi-component nanostructures there must be a match of the interface between materials which may have different crystallographic structures, lattice dimensions, and thermal stability as well as chemical reactivity. New properties may emerge due to the combination of different material systems on the nanoscale. The optical properties of these nanostructures, for example, often exhibit interesting deviations from either their individual components or from a physical mixture of the two components. These optical effects may include a shift in the surface plasmon resonance (SPR) of noble metal nanocrystals when combined or coated with other materials or changes in the photoluminescence intensity of semiconductor nanocrystals [12, 13]. Here we report the synthesis of PVP-capped Au-CdSe hybrid nanoparticles. We have adapted the synthetic methodologies for our recently reported individual PVP-capped Au and cysteine-capped CdSe nanoparticles [14]. The anisotropic, water soluble PVP-capped gold nanoparticles were synthesized using a UV-radiation technique. UV-light was used to reduce Au3+ ions into metal nanoparticles. The concentration of the starting materials, lamp wavelength, and
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