Collaborative Research: Nanocrystal Synthesis Controlled by Functional Carbene Ligands

With the support of the Macromolecular, Supramolecular and Nanochemistry Program in the Division of Chemistry, Profs. Sen Zhang and Michael Hilinski of the University of Virginia, and Prof. Xu Zhang of the California State University Northridge will expand the synthetic toolbox of the nanomaterials chemistry. Controlling the sizes, compositions, and shapes of nanocrystals is crucial for applications in catalysis, optoelectronics, plasmonics, magnetism, and biomedicine. This project will incorporate designed N-heterocyclic carbenes (NHCs) as a new ligand to control over nanocrystal surface facets and sizes. The results shall offer new insights into the fundamental nanochemistry pathways especially the mechanism of NHCs in the formation and modulation of nanocrystals. The knowledge generated could significantly advance research and applications in various fields utilizing functional nanocrystals. Additionally, the project will foster the teaching and training of the next-generation workforce by integrating research and education activities, including outreach to minority-serving institutions. This collaborative project focuses on developing NHC ligands for the colloidal synthesis of noble metal nanocrystals with high-index surfaces. The steric and electronic properties of the NHCs will be independently and systematically adjusted to understand how these perturbations affect nanocrystal formation. By leveraging the combined expertise in nanocrystal synthesis, organic synthesis, catalysis, and quantum mechanics-based multi-scale calculations, the team aims to achieve fundamental advancements in understanding NHC-controlled nanocrystal synthesis. Three specific tasks will be pursued: [1] Preparing a series of NHC ligands and developing the colloidal synthesis of noble metal (Pt, Pd, Au, Ag) nanocrystals under the control of NHC ligands; [2] Elucidating the controlled synthesis mechanism via in-situ characterizations, density functional theory calculations, and machine learning; [3] Understanding the catalytic properties of noble metal nanocrystals with high-index surfaces for CO2 reduction and furfural reduction reactions. Based on a deep understanding of NHC-surface interactions, this project will provide new families of NHC designer ligands that enable the direct synthesis of nanocrystals with controlled surfaces and structures. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.