Atomistic Mechanisms of Gold Nanoparticle Reactivity: Growth, Decomposition, Catalysis, and Ligand Exchange

堪萨斯州立大学的克里斯汀·艾肯斯在大分子、超分子和纳米化学项目的支持下，使用各种理论方法来研究与金和银纳米颗粒生长、分解、催化和配体交换的原子机制有关的基本问题。密度泛函理论将在整个项目中使用，因为它在精度和合理的计算成本之间提供了良好的平衡。连续介质溶剂模型，如COSMO，将被用来研究溶剂极性如何影响反应能学。在催化过程中，耦合的团簇计算将提高势垒高度和反应能的精度。我们将改进经典力场ReaxFF的参数，以便将该方法应用于大尺寸金纳米粒子系统的分子动力学模拟。直径在1-2纳米量级的小尺寸金和银纳米粒子在选择性催化等方面有广泛的应用。以前对这些纳米粒子的理论研究主要集中在它们的结构和/或物理性质上，而不是反应性。在这项研究中，PI将检查影响纳米粒子反应机理的因素。这项研究将有助于更好地控制金和银纳米颗粒的大小和单分散性。此外，它还将确定导致纳米颗粒毒性的因素。此外，这项研究将有助于更好地控制纳米粒子的催化和组装成阵列。此外，这项建议将使国际学生协会能够通过将女性和少数族裔学生纳入研究，继续扩大参与。这项提案的资金将用于帮助本科生和研究生进行研究和传播他们的成果。这些成果将通过同行评议的文件以及在各种机构和会议上的陈述广泛分发。

Christine Aikens of Kansas State University is supported by the Macromolecular, Supramolecular and Nanochemistry program in employing a variety of theoretical methods in order to investigate fundamental questions related to the atomistic mechanisms of gold and silver nanoparticle growth, decomposition, catalysis, and ligand exchange. Density functional theory will be utilized throughout the project since it provides a good balance of accuracy with a reasonable computational cost. Continuum solvent models such as COSMO will be used to examine how solvent polarity affects reaction energetics. Coupled cluster calculations during the catalysis work will improve the accuracy of barrier heights and reaction energies. We will refine parameters for ReaxFF, a classical force field, in order to apply this method to molecular dynamics simulations of large gold nanoparticle systems.Small gold and silver nanoparticles with diameters on the order of 1-2 nanometers have a wide array of applications such as selective catalysis. Previous theoretical studies on these nanoparticles have primarily focused on their structure and/or physical properties rather than reactivity. In this research, the PI will examine factors that affect nanoparticle reaction mechanisms. This research will lead to better control of size and monodispersity of gold and silver nanoparticles. In addition, it will identify factors leading to nanoparticle toxicity. Furthermore, this research will lead to better control of nanoparticle catalysis and assembly into arrays. In addition, this proposal will enable the PI to continue broadening participation through the inclusion of female and minority students in research. Funding from this proposal will be used to assist undergraduate and graduate students as they perform research and disseminate their results. These results will be broadly circulated through peer-reviewed papers and through presentations at a variety of institutions and conferences.