Synthesis of Core-Shell (Pd-Au) Bimetallic Nanoparticles in Microemulsions |
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| Authors: | Eduardo Larios Lilián Calderón Karen Guerrero Emanuel Pinedo Amir Maldonado |
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| Affiliation: | 1. Departamento de Investigación en Polímeros y Materiales , Universidad de Sonora, Hermosillo , Sonora , México;2. Departamento de Ingeniería Química y Metalurgia , Universidad de Sonora , Hermosillo , Sonora , México;3. Departamento de Ingeniería Química y Metalurgia , Universidad de Sonora , Hermosillo , Sonora , México;4. Departamento de Fisica , Universidad de Sonora , Hermosillo , Sonora , México |
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| Abstract: | Palladium-gold core-shell nanoparticles were synthesized in the aqueous domains of water in oil microemulsions by the sequential reduction of H2PdCl4 and HAuCl4. The nanoparticles were characterized by ultraviolet-visible (UV-vis) spectroscopy and transmission electron microscopy (TEM). The UV-vis spectra confirm the presence of palladium nanoparticles after reducing H2PdCl4. These particles have been used as seeds for the core-shell particles. UV-vis spectra show that, after reducing HAuCl4, the surface plasmon absorption of the nanoparticles is dominated by gold, revealing the encapsulation of the palladium seeds. These results agree with crystallographic analysis performed with high-resolution TEM pictures, as well as with selected area electron diffraction. The TEM pictures show the core-shell nanoparticles with an average diameter of 9.1 nm, as compared with 5 nm for the palladium seeds, in good agreement with the used Pd:Au molar ratio. |
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| Keywords: | Core-shell microemulsions nanoparticles palladium-gold |
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