Using atoms as elemental building blocks to construct nanoscale functional materials is of major importance in materials research. This project focuses on the development of new methodologies for precise assembly of metal atoms into functional nanoparticles, and the investigation of how the properties of these materials depend on nanoparticle size. This project offers new opportunities for exploring the novel properties of atomically precise metal nanoparticle materials, bringing broad impact across several important areas. Leveraging our capability of manipulating the bonding between atoms to achieve new functionalities, this project is set to impact fields such as catalysis, energy conversion, chemical sensing and biomedicine. This research effort additionally enables impact on regional outreach and educational activities. Graduate and undergraduate students participating in this project receive interdisciplinary training, which contributes to their future careers in the increasingly competitive and fast-moving area of materials research.
Metal nanoparticles (e.g. Au, Ag) are being intensely pursued owing to their unique plasmon properties. Ultrasmall metal nanoparticles (<3 nm) no longer exhibit metallic properties, with the plasmon disappearing due to quantum size effect. However, the fundamental origin of plasmons has not been elucidated due to the difficulties in controlling the atomic monodipsersity and structural uniformity of ultrasmall nanoparticles. This project tackles the challenges of creating atomically precise nanoparticles, and conducts a systematic investigation of the evolutionary behavior from the quantized state to the metallic/plasmonic state. The proposed research expands the current understanding of metal nanomaterials. Probing the transition behavior in gold nanoparticles is used to establish a model approach for future studies of other metal nanoparticle systems (e.g., Ag, Cu, bimetals.) The educational component of the project broadens student participation by engaging high school students and teachers, some of whom are from underrepresented minority groups. The educational efforts help attract students into science and technology by cultivating their research interests and through participation in materials research.
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.
