Electrochemistry as a Design Tool for Colloidal Syntheses of Polyhedral Metal Nanoparticles

With the support of the Macromolecular, Supramolecular and Nanochemistry Program in the Division of Chemistry, Dr. Michelle L. Personick of Wesleyan University will use real-time electrochemical measurements to probe the growth of nano-sized metal particles. Metal nanoparticles have useful applications in sensing, biomedical imaging, and catalysis for chemical manufacturing and generation of sustainable fuels. Their optical properties and catalytic performance can be tailored not only by controlling their composition and size, but also their shape. This research aims to understand nanoparticle growth mechanisms and establish core chemical principles to inform the deliberate, predictive design of metal nanomaterials to meet the increasingly complex needs of emerging applications. Graduate, undergraduate, and high school students who are involved in this research will be prepared for future careers at the interface of chemistry, materials science, and chemical engineering. The project will also contribute to enhancing participation in science and research by developing publicly available resources to increase the accessibility of undergraduate science for students who are the first in their family to pursue this course of study. This project focuses on an important, but largely unexplored, area of fundamental research in using electrochemical nanoparticle synthesis as a tool to understand nanoparticle growth mechanisms and to predictively design colloidal synthetic strategies. Dr. Personick’s research team pioneers an innovative, integrated electrochemical approach for elucidating the underlying chemical factors that control the reduction of metal ions at surfaces during the growth of metal nanoparticles. This approach will involve dynamic feedback between electrochemical measurements of metal ion reduction under complex conditions, electrochemically driven nanoparticle growth on electrode surfaces under well-defined conditions, and colloidal nanoparticle growth using chemical reducing agents. This research aims to overcome key challenges in nanomaterials synthesis by (1) enabling real-time monitoring of the chemical reactions and mechanisms of metal nanoparticle growth; (2) introducing added flexibility in the composition of nanoparticle growth solutions to separately define the mechanistic influences of chemical parameters that are not distinguishable in standard colloidal synthesis; and (3) providing a route to the directed design of noble metal nanoparticles with currently unachievable architectures and compositions. 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.