Nanocrystal Conversion Pathways for the Synthesis of Multimetallic Nanostructures

在化学系大分子、超分子和纳米化学(MSN)计划的支持下，印第安纳大学布鲁明顿分校的Sara Skrabalak教授将开发制造纳米尺度多金属材料的新方法。纳米尺度的金属颗粒具有与块状材料不同的迷人特性。例如，块状黄金显示为有光泽的黄色，而纳米级黄金可以根据颗粒大小和形状出现许多不同的颜色，从而产生了彩色玻璃的鲜艳颜色。金属颗粒的纳米级特性现在正被用于促进可持续性、安全性、健康等方面的技术。然而，由两种或两种以上金属组成的纳米级颗粒的一般合成远远不太发达。Skrabalak小组的目标是开发具有明确结构和组成特征的多金属纳米颗粒的可预测和可推广的合成。该项目将在包容的环境中为研究生提供强有力的培训。此外，这项研究还将结合广泛的教育和宣传活动，促进对纳米材料的了解，包括与当地艺术家和非科学家一起通过“十次幂”概念探索规模的重要性。斯克拉巴拉克教授和她的学生将与印第安纳州布鲁明顿艺术委员会合作，为创作一幅公共壁画寻找地点和艺术家，探索大小和规模及其对公共生活的重要性。公众对这一主题的探索活动将被开发用于壁画的首次亮相和随后的推广活动。多金属纳米颗粒的合成将从已知的纳米颗粒开始，然后通过物理和化学方法将其转化为更复杂的纳米颗粒。纳米粒子的转化途径将集中在两类纳米粒子上。首先，将通过加热核壳纳米粒子来合成高熵合金金属纳米粒子-由五个或五个以上元素组成的多元素单相材料，以促进相互扩散。它们的形成机制将通过监测晶相和元素分布的变化来确定。新的构图也将成为目标。其次，通过多金属纳米颗粒与金属前驱体之间的电偶置换，制备出具有不同金属结构域的纳米颗粒异质结构。不同纳米粒子异质结构的形成机制将被阐明，以获得具有集成的原子和纳米尺度结构的粒子。还将研究这些复杂纳米颗粒的组成和结构特性。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 (MSN) Program in the Division of Chemistry, Professor Sara Skrabalak at Indiana University – Bloomington will develop new ways of making multimetallic materials with nanoscale dimensions. Metal particles with nanoscale dimensions have fascinating properties that differ from bulk materials. For example, bulk gold appears as a lustrous yellow color while nanoscale gold can appear many different colors depending on particle size and shape, having given rise to the brilliant colors of stained glass. The nanoscale properties of metal particles are now being leveraged in technologies that promote sustainability, security, health, and more. However, general syntheses for nanoscale particles composed of two or more metals are far less developed. The Skrabalak group aims to develop predictable and generalizable syntheses for multimetallic nanoparticles with defined structural and compositional features. This project will provide robust training for graduate students in an inclusive environment. In addition, this research will be coupled with broad educational and outreach initiatives that promote understanding of nanoscale materials, including exploration of the importance of scale through the “Powers of Ten” concept with local artists and non-scientists. Professor Skrabalak and her students will work with the Art Commission of Bloomington, Indiana to identify a site and artist for the creation of a public mural that explores size and scale and their importance to public life. Activities for the public’s exploration of this topic will be developed for use during the mural’s debut and subsequent outreach events.The synthesis of multimetallic nanoparticles will start with known nanoparticles, which will then be converted into more complex nanoparticles by physical and chemical methods. The nanoparticle conversion pathways will focus on two nanoparticle classes. First, high entropy alloy metal nanoparticles – multi-element, single-phase materials consisting of five or more elements in similar atomic ratios – will be synthesized by heating core@shell nanoparticles to facilitate interdiffusion. The mechanism that accounts for their formation will be determined by monitoring changes in crystal phase and elemental distribution. New compositions also will be targeted. Second, nanoparticle heterostructures with different metal domains will be synthesized by galvanic replacement between multimetallic nanoparticles and metal precursors. The mechanism that accounts for the formation of different nanoparticle heterostructures will be elucidated to achieve particles with integrated atomic and nanoscale architectures. The compositional and structural properties of these complex nanoparticles will also be studied.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.