The origin of the catalytic efficiency and the plasmonic optical properties of different types of hollow nanostructures

在这个由化学系大分子、超分子和纳米化学项目资助的项目中，格鲁吉亚理工学院的Mostafa El-Sayed教授开发了纳米颗粒作为催化剂。 纳米粒子是包含数千个原子的微小粒子。 虽然它们比只包含几个原子的化学分子大得多，但纳米颗粒比固体材料小，固体材料大到足以用肉眼看到。 纳米颗粒也是不寻常的，因为大部分原子在表面或非常接近表面，因此纳米结构的原子与大气或周围液体的重排，交换和添加比与相同气体或液体接触的大块固体容易得多，其中原子通常在固体内部并且不可接近。 纳米颗粒具有非常大的表面积，催化化学反应发生，并可用于许多领域，如快速化学生产，可持续能源和材料化学。 El-Sayed教授开发了超快方法来制造相同或更好的材料。 这些方法可以大大提高材料的生产率，并为制造具有实际意义的新产品提供新的方法。该项目为研究生提供了研究机会。它还包括通过与历史上的黑人学院和大学（HBCUs）的互动，针对代表性不足的群体成员的外联活动。在这个项目中，设计了具有小等离子体纳米颗粒的纳米阵列催化剂的形状，尺寸和组成，以优化其催化性能。这些新设计的等离子体纳米晶格的光学和催化性能正在理论和实验上进行研究。使用表面增强拉曼光谱（Sers）探测涉及纳米晶格的催化反应中涉及的机制。该方法允许区分可能导致反应的催化增强的几种可能的效应。该项目还研究了纳米塔内部颗粒的移动方式，并将其催化效率与气相反应进行了比较。研究小组还准备了催化剂-金属混合纳米颗粒，使用超快光谱研究它们的催化性能和电荷载体行为，并检查它们的机械稳定性。

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.