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

在化学系大分子、超分子和纳米化学项目的支持下，匹兹堡大学的吉尔·e·米尔斯顿教授正在开发利用可见光制造纳米材料的新方法。在分子化学中，光是一种强大的工具，可以提高反应效率、精度和可持续性。然而，在纳米材料的合成中，光是一种不太常见的试剂，但可以提供类似的增益。该项目旨在为材料合成开辟一条新途径，有望在结构控制和纳米级物质形成的基本化学理解方面取得进展。实施该项目所需的方法的多样性将为学生提供尖端的教育和培训，并使他们成为未来各种技术和教学环境中的领导者。研究和教育的联系是这项工作的核心，包括培训本科生，将其纳入研究生和本科课程，以及向广泛的利益相关者(包括初级教师，高中科学教师，K-12学生和基于社区的STEM（科学，技术，工程和数学）努力开展外展活动。这项工作的目的是开发利用光在化学合成中的优势的方法，特别是使用催化、光氧化还原介导的纳米颗粒合成来阐明双金属纳米颗粒的成核如何影响它们的大小、化学计量和化学顺序。迄今为止，催化光还原为纳米颗粒的形成提供了一种新的途径，这在传统的基于化学还原的合成中是没有观察到的，包括纳米颗粒的连续形成以及颗粒形成后的抑制生长。研究影响纳米颗粒连续成核和抑制纳米颗粒生长的关键合成参数，包括金属离子还原速率和纳米颗粒表面化学。这种新的粒子形成途径将用于了解金属原子与多金属纳米粒子的结合，作为粒子大小和形成速率的函数。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

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.