A General and Robust Route to Highly Diverse Hollow Nanostructures with New Properties

非技术概述具有中空内部的纳米材料(即中空纳米材料)是许多科学技术领域的关键部件。中空纳米材料的性质及其在生物传感和催化等应用中的应用强烈依赖于其形状和元素组成等详细结构，并且可能不同于相同尺寸的固体颗粒。然而，在化学合成中，如何精确控制中空纳米材料的结构一直是一个挑战。该项目由材料研究部的固体与材料化学计划和金属与金属纳米结构计划共同支持，其目标是建立一种通用而有效的方法来合成具有可控结构和新性能的中空纳米材料。除了合成新材料外，该项目还研究热稳定性和与光的异常相互作用等性能，这对最终的应用将是重要的。该项目为研究生和本科生提供多学科研究培训，特别是来自代表性不足群体的培训。通过一项新的纳米大使计划，本科生将在以前的高中参与纳米材料的推广活动。该项目还为高中生提供了暑期研究机会。技术总结空心纳米材料在许多领域得到了广泛的应用，包括生物医学、成像、传感、催化和电子技术。控制中空纳米结构的结构是调整其物理化学性质的有效途径。这项拟议的工作得到了材料研究部固态和材料化学计划以及金属和金属纳米结构计划的联合支持，旨在开发一种通用而稳健的方法来精确控制空心纳米材料的结构。该方法依赖于电偶取代反应和牺牲模板再生的交替过程。作为例子，正在展示由金、银、铂、钯、铜和含有多种金属的材料制成的中空纳米结构的设计和合成。一系列具有不同结构和新性质的中空纳米结构正在被产生。用高性能电子显微镜揭示了空心纳米材料的详细结构及其对加热的结构响应。通过实验测量和计算模拟研究了纳米材料的等离子体激元性质。这个项目将有利于研究生和本科生，特别是那些来自代表性不足的群体的学生，参与研究。这项研究还纳入了针对K-12学生的外展活动。通过一项新的纳米大使计划，本科生将在以前的高中参与纳米材料的推广活动。该项目还为高中生提供暑期研究机会。该奖项反映了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。

Non-Technical Summary Nanoscale materials with hollow interiors (i.e., hollow nanomaterials) are critical components in many areas of science and technology. The properties of hollow nanomaterials and their usefulness in applications such as biosensing and catalysis have strong dependence on their detailed structure such as shape and elemental composition and can be different than those of solid particles of the same size. Nevertheless, it has been a challenge to finely control the structure of a hollow nanomaterial in chemical synthesis. The goal of this project, which is jointly supported by the Solid State and Materials Chemistry program and the Metals and Metallic Nanostructures program, both in the Division of Materials Research, is to establish a general and effective method to synthesize hollow nanomaterials with controllable structures and new properties. In addition to synthesizing new materials, this project examines properties such as thermal stability and unusual interactions with light that will be important for eventual applications. This project provides multidisciplinary research training for graduate and undergraduate students particularly from underrepresented groups. Through a new NanoAmbassadors program, undergraduate students will be involved in outreach on nanomaterials at their former high schools. The project also provides high school students with summer research opportunities.Technical SummaryHollow nanomaterials have found widespread uses in many areas, including biomedicine, imaging, sensing, catalysis and electronics. Controlling the structure of hollow nanostructures is an effective approach to tailoring their physicochemical properties. The proposed work, which is jointly supported by the Solid State and Materials Chemistry program and the Metals and Metallic Nanostructures program, both in the Division of Materials Research, seeks to develop a general and robust method to precisely control the structure of hollow nanomaterials. This method relies on alternating processes of galvanic replacement reactions and sacrificial template regeneration. As examples, design and synthesis of hollow nanostructures made of gold, silver, platinum, palladium, copper, and materials containing multiple metals are being demonstrated. A series of hollow nanostructures with diverse structures and new properties are being generated. Detailed structures of the hollow nanomaterials and their structural responses to heating are revealed with high-performance electron microscopy. Plasmonic properties of the nanomaterials are investigated using both experimental measurements and computational simulations. This project will benefit the engagement of graduate and undergraduate students, especially those from underrepresented groups, in research. The research is also integrated into outreach activities for K-12 students. Through a new NanoAmbassadors program, undergraduate students will be involved in outreach on nanomaterials at their former high schools. The project also provides high school students with summer research opportunities.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.