Bimetallic Janus Nanocrystals and Their Derivatives

双金属Janus纳米晶及其衍生物

• 批准号: 1804970
• 负责人: Younan Xia
• 金额: $ 42.27万
• 依托单位: Georgia Tech Research Corporation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-09-01 至 2022-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1804970&HistoricalAwards=false
• 关键词: Bimetallic; Janus; Nanocrystals; Their; Derivatives

Assemblies of metal atoms with well-ordered structures in the size range of ~10 nanometers are known as nanocrystals. Controlling the spatial distributions of different metal atoms in nanocrystals offers a simple and versatile way to tailor their structures and properties. Such tailoring has the potential to vastly expand their utility as catalysts in the production of important chemicals and pharmaceuticals as well as processes used for conversion of energy and protection of the environment. In this project, Dr. Younan Xia of the Georgia Institute of Technology and Dr. Manos Mavrikakis of the University of Wisconsin-Madison are developing a bimetallic system, in which the two metals are spatially separated from each other by an interface to form nanocrystals with a Janus structure. The bimetallic Janus nanocrystals offer a broad range of unique properties and applications, including the tuning of optical response and the enhancement of catalytic activity and/or selectivity for specific chemical products. By switching to bimetallic Janus nanocrystals and their derivatives, one can substantially reduce the amount of precious metal in a nanocrystal while potentially improving the performance, enabling Society to achieve cost-effective and sustainable use of precious metals, some of the scarcest elements in the Earth's crust. However, there are only a very limited number of reports on bimetallic Janus nanocrystals, primarily due to the lack of mechanistic understanding and experimental control for their chemical synthesis. As a major requirement for the formation of bimetallic Janus nanocrystals, the atoms of one metal can only be deposited at a single site on the surface of a nanocrystal made of another metal and this particular pattern of deposition must be maintained throughout the growth process. The PIs integrate experimental studies and computational modeling in their development of predictable, deterministic, and robust synthesis of bimetallic Janus nanocrystals. They are also contributing to the preparation of a skilled workforce for science, technology, engineering and mathematics (STEM) disciplines through active engagement of graduate and undergraduate students in this collaborative, multidisciplinary research, as well as curriculum enrichment and development. The investigators are fully committed to promoting diversity in higher education by engaging underrepresented groups into this research project. With funding from the Macromolecular, Supramolecular & Nanochemistry (MSN) Program of the Chemistry Division, Drs. Xia and Mavrikakis are developing a new knowledge base for the design and deterministic synthesis of bimetallic Janus nanocrystals. They are deriving the exact range of initial reduction rate needed for achieving nucleation and growth from a single site on each individual nanocrystal and thus generating a Janus structure. They are also investigating the thermal stability of the Janus nanocrystals with respect to atomic inter-diffusion and surface diffusion. As for applications, the Janus nanocrystals are explored as building blocks for colloidal self-assembly and as sacrificial templates for the fabrication of metal nanoboxes with a single, well-defined hole on the surface, preferably located at one of the vertices. Such nanoboxes, when made of platinum, can serve as a highly active and durable catalyst towards oxygen reduction, a reaction key to the operation of hydrogen-based fuel cells. Along with the experimental studies, computational modeling is used to explain the trends and mechanisms involved in the syntheses, as well as the catalysis taking place on some of the bimetallic nanocrystals.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.

尺寸范围约为 10 纳米、具有良好有序结构的金属原子组件被称为纳米晶体。控制纳米晶体中不同金属原子的空间分布提供了一种简单而通用的方法来定制其结构和性能。这种定制有可能极大地扩展其作为重要化学品和药品生产以及能源转换和环境保护过程中催化剂的用途。在这个项目中，佐治亚理工学院的 Younan Xia 博士和威斯康星大学麦迪逊分校的 Manos Mavrikakis 博士正在开发一种双金属系统，其中两种金属通过界面在空间上彼此分离，形成纳米晶体杰纳斯结构。双金属 Janus 纳米晶体具有广泛的独特性能和应用，包括调整光学响应以及增强特定化学产品的催化活性和/或选择性。通过改用双金属 Janus 纳米晶体及其衍生物，可以大幅减少纳米晶体中贵金属的含量，同时潜在地提高性能，使社会能够实现贵金属（地球上最稀缺的元素之一）的经济高效和可持续利用。地壳。然而，关于双金属 Janus 纳米晶体的报道数量非常有限，这主要是由于缺乏对其化学合成的机理理解和实验控制。作为形成双金属 Janus 纳米晶体的主要要求，一种金属的原子只能沉积在另一种金属制成的纳米晶体表面的单个位点上，并且必须在整个生长过程中保持这种特定的沉积模式。 PI 将实验研究和计算模型结合到可预测、确定性和稳健的双金属 Janus 纳米晶体合成的开发中。他们还通过研究生和本科生积极参与这一协作性、多学科研究以及课程丰富和开发，为科学、技术、工程和数学 (STEM) 学科培养一支熟练的劳动力队伍做出贡献。研究人员完全致力于通过让代表性不足的群体参与该研究项目来促进高等教育的多样性。在化学部高分子、超分子和纳米化学（MSN）项目的资助下，博士。 Xia 和 Mavrikakis 正在开发一个新的知识库，用于双金属 Janus 纳米晶体的设计和确定性合成。他们正在推导出从每个纳米晶体上的单个位点实现成核和生长所需的初始还原率的精确范围，从而生成 Janus 结构。他们还在研究 Janus 纳米晶体在原子相互扩散和表面扩散方面的热稳定性。至于应用，Janus 纳米晶体被探索作为胶体自组装的构建块，以及作为制造金属纳米盒的牺牲模板，该金属纳米盒的表面上有一个明确的孔，最好位于其中一个顶点。这种纳米盒由铂制成，可以作为氧还原的高活性和耐用催化剂，氧还原是氢基燃料电池运行的关键反应。与实验研究一起，计算模型被用来解释合成中涉及的趋势和机制，以及一些双金属纳米晶体上发生的催化作用。该奖项反映了 NSF 的法定使命，并通过评估被认为值得支持利用基金会的智力优势和更广泛的影响审查标准。

项目成果

Kinetically Controlled Synthesis of Pd–Cu Janus Nanocrystals with Enriched Surface Structures and Enhanced Catalytic Activities toward CO 2 Reduction

动力学控制合成具有富集表面结构和增强 CO 2 还原催化活性的 Pd-Cu Janus 纳米晶

• DOI: 10.1021/jacs.0c05408
• 发表时间: 2021-01
• 期刊: Journal of the American Chemical Society
• 影响因子: 15
• 作者: Lyu, Zhiheng;Zhu, Shangqian;Xu, Lang;Chen, Zitao;Zhang, Yu;Xie, Minghao;Li, Tiehuai;Zhou, Shan;Liu, Jingyue;Chi, Miaofang;et al
• 通讯作者: et al

Pencil-Like Ag Nanorods Asymmetrically Capped by Pd

钯不对称覆盖的铅笔状银纳米棒

• DOI: 10.1021/acs.chemmater.0c01837
• 发表时间: 2020-05
• 期刊: Chemistry of Materials
• 影响因子: 8.6
• 作者: Zhou, Li;Lyu, Zhiheng;Xia, Younan
• 通讯作者: Xia, Younan

Facile Synthesis of Pd−Cu Bimetallic Twin Nanocubes and a Mechanistic Understanding of the Shape Evolution

Pd-Cu双金属孪生纳米立方体的简便合成以及形状演化的机理理解

• DOI: 10.1002/cnma.201900653
• 发表时间: 2020-03-01
• 作者: Yifeng Shi;Zhiheng Lyu;J. Liu;Emily Chase;Younan Xia
• 通讯作者: Younan Xia

Mechanistic Study of Seed-Mediated Growth of Gold Rhombic Dodecahedra

金菱形十二面体种子介导的生长机理研究

• DOI: 10.1021/acs.jpcc.1c08288
• 发表时间: 2021-12
• 期刊: The Journal of Physical Chemistry C
• 作者: Zhao, Xiaohuan;Pawlik, Veronica D.;Huo, Da;Zhou, Shan;Yang, Bai;Xia, Younan
• 通讯作者: Xia, Younan

Facile Synthesis of Platinum Right Bipyramids by Separating and Controlling the Nucleation Step in a Continuous Flow System

通过在连续流系统中分离和控制成核步骤轻松合成铂直位双锥体

• DOI: 10.1002/chem.202101988
• 发表时间: 2021-10
• 期刊: Chemistry – A European Journal
• 作者: Chen, Ruhui;Shi, Yifeng;Xie, Minghao;Xia, Younan
• 通讯作者: Xia, Younan