Synthesis and properties of core-shell structure of triangular Ag@Au

• Main Author: Satkunarajah Pratheepan.
• Other Authors: Xue Can
• Format: Final Year Project
• Language: English
• Published: 2011
• Subjects: DRNTU::Engineering::Materials::Nanostructured materials
• Online Access: http://hdl.handle.net/10356/44016
• Institution: Nanyang Technological University

Nanotechnology has received attention recently due to its ability to offer different material properties from the same material in the bulk phase. Gold and silver have, in particular, generated much interest due to the unique optical properties. Bimetallic nanoparticles offer a greater range of properties. Bimetallic structures, when combined with anisotropy in structures, can give rise to core shell nano particles. As geometric dimensions play an important role in the properties of such particles, a variety of properties can be obtained by varying the size and shape of the particle. In this study, silver nanoprisms are used as a template to coat gold onto the surface. This is done using galvanic potential as the driving force for gold to be reduced onto the surface of the prism. A series of experiments are done to first optimize the synthesize route to ensure that the final coating is uniform and that the prismatic structure is maintained even after the coating process. The factors that affect the coating process will be studied and optimized to get perfectly coated prisms. These factors include, concentration of reagents, edge length of the prisms, temperature, rate of injection, pH of both the prisms and reagents and the speed of stirring Characterization is performed using UV Vis spectroscopy and Transmission Electron Microscopy, at various intervals during and after the coating process to study the effect of the factors mentioned earlier. Optimization of the process also aims to avoid and/or reduce defects in the morphology such as truncation and etching.