In this project funded by the Macromolecular, Supramolecular and Nanochemistry Program in the Division of Chemistry, Professor Mostafa El-Sayed of the Georgia Institute of Technology develops nanoparticles as catalysts. Nanoparticles are tiny particles that contain thousands of atoms. While they are much larger than chemical molecules, which contain only a few atoms, nanoparticles are smaller than solid materials that are large enough to see with the naked eye. Nanoparticles are also unusual in that a large fraction of the atoms are at or very near the surface, so rearrangement, exchange and addition of atoms in the particle with the atmosphere or a surrounding liquid is much easier for a nanostructure than for a bulk solid in contact with the same gas or liquid, where the atoms are typically inside the solid and not accessible. Nanoparticles have very large surface areas where catalytic chemical reactions take place, and can be used in numerous fields such as fast chemical production, sustainable energy, and material chemistry. Professor El-Sayed develops ultrafast methods to make the same or better material. These methods can greatly increase the rate of production of material and lead to new ways to make new products of practical importance. This project provides research opportunities for graduate students. It also includes outreach activities aimed at members of underrepresented groups through interactions with Historically Black Colleges and Universities (HBCUs).
In this project, the shape, size, and composition of nanorattle catalysts with small plasmonic nanoparticles are engineered to optimize their catalytic performance. The optical and catalytic properties of these newly designed plasmonic nanorattles are being studied both theoretically and experimentally. The mechanisms involved in the catalytic reactions involving nanorattles are probed using surface-enhanced Raman spectroscopy (SERS). This methods allows the distinction between several possible effects that could lead to catalytic enhancement of the reactions. The project also examines how the interior particles in the nanorattles move, and compares their catalytic efficiency with gas phase reactions. The research team also prepares semiconductor-metal hybrid nanoparticles to study their catalytic properties and charge carrier behavior using ultrafast spectroscopy, and examines their mechanical stabilities.