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，Jill E.匹兹堡大学的Millstone正在开发利用可见光制造纳米材料的新方法。光一直是分子化学中的强大工具，可以提高反应效率，精确度和可持续性。然而，光在纳米材料的合成中是一种不太常见的试剂，但可以提供类似的收益。该项目旨在为材料合成开辟一条新的途径，有望在结构控制和对纳米级物质如何形成的基本化学理解方面取得进展。开展这一项目所需方法的多样性将为学生提供最先进的教育和培训，并使他们成为各种技术和教学环境中的未来领导者。研究和教育的联系是这项工作的核心，涉及培训本科生，纳入研究生和本科生课程，以及与包括初级教师，高中科学教师，K-12学生和社区STEM在内的广泛利益相关者的外联活动。这项工作的目标是开发利用光在化学合成中的优势的方法，并且具体地使用催化的光氧化还原介导的纳米颗粒合成来阐明纳米颗粒的成核如何影响它们的尺寸、化学计量和化学排序。到目前为止，催化光还原提供了一种新的纳米颗粒形成途径，这在传统的基于化学还原的合成中没有观察到，包括纳米颗粒的连续形成以及一旦形成就抑制颗粒生长。关键的合成参数有助于连续的纳米粒子成核和抑制纳米粒子的生长将进行研究，包括金属离子还原率和纳米粒子表面化学。这一新的颗粒形成途径将被用于了解金属原子掺入多金属纳米颗粒作为粒径和形成率的函数。该奖项反映了NSF的法定使命，并已被认为值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

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.