EAGER: Understanding Photocatalytic Reduction-Enabled Continuous Nucleation of Multimetallic Nanoparticles

University Of Pittsburgh, Pittsburgh PA

Investigators

Abstract

With the support of the Macromolecular, Supramolecular, and Nanochemistry Program in the Division of Chemistry, Professor Jill E. Millstone of the University of Pittsburgh is developing new ways to make nanomaterials using visible light. Light has been a powerful tool in molecular chemistry, leading to gains in reaction efficiency, precision, and sustainability. However, light is a much less common reagent in the synthesis of nanomaterials but could afford similar gains. This project aims to opens a new avenue for materials synthesis that promises advances in both structural control and fundamental chemical understanding of how nanoscale matter forms. The diverse nature of methodologies necessary to carry out this project will provide cutting edge education and training for students and prepare them to be future leaders in a variety of technical and pedagogical settings. The connection of research and education are central to this work and involve training undergraduates, incorporation into both graduate and undergraduate curricula, and outreach activities to a wide range of stakeholders including junior faculty, high school science teachers, K-12 students, and community-based STEM (science, technology, engineering and mathematics) efforts. The objective of this work is to develop methods that leverage the advantages of light in chemical synthesis, and specifically to use a catalytic, photoredox-mediated nanoparticle synthesis to elucidate how the nucleation of bimetallic nanoparticles impacts their size, stoichiometry, and chemical ordering. Thus far, catalytic photoreduction provides a new pathway to nanoparticle formation that is not observed in traditional chemical reduction-based syntheses, including the continuous formation of nanoparticles as well as suppression of particle growth once formed. Key synthetic parameters contributing to both continuous nanoparticle nucleation and suppressed nanoparticle growth will be studied, including metal ion reduction rate and nanoparticle surface chemistry. This new particle formation pathway will then be used to understand metal atom incorporation into multimetallic nanoparticles as function of particle size and formation rate. 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.