Synthesis, characterization, and catalysis of metal nanoparticles

The goal of the dissertation work is the understanding of the physical and chemical properties of materials in the nanoscale regime. As discussed in this dissertation, the goal is accomplished by specifically focusing on the investigation of the synthesis and characterization of metal nanoparticles and supported catalysts. The findings have provided us with new and important insights into the physical and chemical properties of metal nanoparticles and supported catalysts. Several new routes allowed us to synthesize copper, gold-platinum, core-shell nanoparticles with monodispersed sizes, controlled shapes and tunable surface properties. For example, we have demonstrated the ability to control the formation of copper nanorods with high monodispersity and ordering by controlled thermal processing. Another of our studies has focused on the exploitation of the synergistic properties of multimetallic nanoparticles by monitoring the CO adsorption on bimetallic gold-platinum nanoparticles using infrared spectroscopy. The size correlation between using different microscopic techniques such as TEM and AFM has been established for the size determination of nanoparticles. This correlation is important in understanding their physical or chemical properties of nanoparticles on different substrate surfaces. The quantitative correlation demonstrates the ability of AFM in determining sizes of nanoparticles, which has implications to the understanding of the relative radius of curvature of the tip vs. the particle sizes as well as the surface properties of the particles. The preliminary results using computational modeling to elucidate some of the surface binding and energy properties of nanoparticles provides some guidelines to experimental measurements, and also helps in the explanation of the complex experimental data. Overall, these findings and results have provided new insights into the fundamental factors governing the physical and chemical properties in the synthesis and application of metal nanoparticles and supported catalysts. Part of the ongoing work includes a study of the chemical sensing properties of the thin film assembly of the nanoparticles, and computational modeling to identify promising catalysts with specific catalytic or surface properties. The results of these studies will be useful for the design of advanced functional nanomaterials.