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·米尔斯通教授正在开发利用可见光制造纳米材料的新方法。光已经成为分子化学中的一个强大工具，导致了反应效率、精确度和可持续性的提高。然而，在纳米材料的合成中，光是一种不太常见的试剂，但可以获得类似的收益。该项目旨在为材料合成开辟一条新的途径，承诺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先进的教育和培训，并使他们为将来成为各种技术和教学环境的领导者做好准备。研究与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，以及与广泛的利益相关者开展推广活动，包括初级教师、高中科学教师、K-12学生和社区STEM(科学、技术、工程和数学)工作。这项工作的目标是开发在化学合成中利用光的优势的方法，特别是使用催化、光氧化还原介导型纳米颗粒合成来阐明双金属纳米颗粒的成核如何影响其尺寸、化学计量比和化学有序性。到目前为止，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一旦形成就抑制了颗粒的生长。将研究有助于纳米颗粒持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。这一新的颗粒形成途径将被用来理解金属原子作为颗粒大小和形成速率的函数被纳入多金属纳米颗粒中。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.