CAREER: Room Temperature Electrochemical Synthesis of Ordered Intermetallic Nanomaterials

职业：有序金属间纳米材料的室温电化学合成

基本信息

批准号：
2047019
负责人：
Anthony Hall
金额：
$ 57万
依托单位：
Johns Hopkins University
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
2021
资助国家：
美国
起止时间：
2021-07-01 至 2026-06-30
项目状态：
未结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=2047019&HistoricalAwards=false
关键词：
CAREER Room Temperature Electrochemical Synthesis

项目摘要

Non-Technical Summary:Ordered intermetallic compounds (OICs) are metallic alloys with a periodic atomic arrangement of two (or more) metal elements. These OICs play an important role in technologies such as catalysis, batteries, and shape-memory alloys. Their application space is limited, however, because these materials can only be prepared at high temperatures, often eroding control over important material parameters. Making the low-temperature synthesis of OICs possible requires a precise understanding of how atoms move within solid materials. This Faculty Early Career Award (CAREER) will support research in the laboratory of Dr. Anthony Shoji Hall at the Johns Hopkins University to examine pathways that allow for the control of atom movement at low temperatures and thereby enable the preparation of ordered intermetallic nanomaterials at room temperature and atmospheric pressure. By enabling the synthesis of these materials at low temperatures, this work will substantially broaden the application space of OICs because it now allows for more fine control over important materials parameters. Dr. Hall’s laboratory will actively share their scientific passion and discoveries with the broader community by engaging in outreach at inner-city Baltimore high schools and universities. The first activity will leverage an established program, STEM achievement in Baltimore elementary schools (SABES), to encourage elementary students to pursue a degree in STEM. This project will also create a new program to encourage URM high school students to pursue degrees in STEM and to improve the retainment of URM (under)graduate students in STEM careers. Technical Summary:Despite decades of intense research, OIC nanoparticles have failed to replace conventional nanomaterials due to (1) lack of low-temperature synthetic methods that can overcome slow solid-state diffusion rates which inhibits atomic ordering, (2) inability to tune composition and phase to optimize the desired application, and (3) lack of fundamental understanding needed for progress on these issues. The purpose of this CAREER proposal is to examine the phase transformations of low melting point alloys to higher melting point OICs richer in the nobler and more active metal at ambient temperature and pressure by removal of the less noble component (e.g., transforming PdBi2 to Pd3Bi, or CuZn4 to Cu5Zn8) via a process known as dealloying. Fundamental insights from this project will enable the rational development of OIC nanostructures for applications of technological relevance and improve our understanding of material stability under electrocatalytic conditions. To understand the origin of the electrochemical dealloying-mediated phase conversion process, the PI will investigate the following objectives: (1) Elucidate the role of melting temperature on bulk diffusion and lattice reorganization. (2) Develop synthesis methods for controlled compositions of de-alloyed OICs. (3) Elucidate dealloying via in-situ spectroscopic methods. Materials made by this electrochemically mediated phase conversion process will be evaluated as anodes for Li-metal batteries to demonstrate the utility of the synthetic method. The broader impacts of this proposal will encourage underrepresented minority (URM) K-12 students and (under)graduate students to pursue careers in STEM through engagement in outreach programs. URM students lack access to relatable role models in STEM fields because of underrepresentation. To address this issue, Dr. Hall will make himself available for informal “coffee hour discussions” to serve as a mentor and role model for URM students (high school-aged, undergraduate, and graduate students) in the Baltimore area. The Hall group will also work with K-12 aged URM students on inquiry-based scientific projects by participating in the STEM Achievement in Baltimore Elementary Schools (SABES) program.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.

非技术摘要：有序的金属间化合物（OIC）是金属合金，具有周期性的原子布置，分为两个（或更多）金属元件。这些OIC在诸如催化剂，电池和形状 - 内存合金等技术中起着重要作用。但是，它们的应用空间受到限制，因为这些材料只能在高温下制备，通常会侵蚀对重要材料参数的控制。使oics的低温合成可能需要精确理解原子在固体材料中的移动。该教师早期职业奖（职业）将支持约翰霍普金斯大学安东尼·肖吉·霍尔博士的实验室研究，以检查途径，以允许在低温下控制原子运动，从而使室内温度和大气压下有序的金属纳米材料进行准备。通过在低温下启用这些材料的合成，这项工作将大大拓宽OIC的应用空间，因为它现在可以对重要材料参数进行更多的精细控制。霍尔博士的实验室将通过在巴尔的摩市中心高中和大学进行外展，积极地与更广泛的社区分享他们的科学热情和发现。第一项活动将利用已建立的计划，即巴尔的摩小学（SAB）的STEM成就，以鼓励小学生购买STEM学位。该项目还将创建一个新的计划，以鼓励URM高中学生购买STEM学位，并提高STEM职业生涯中URM（下）研究生的保留。技术摘要：尽管进行了数十年的深入研究，但OIC纳米颗粒仍未取代传统的纳米材料，因为（1）缺乏低温合成方法，这些方法可以克服抑制原子质的慢速固体扩散率，而抑制原子序的稳定性，（2）无法调整成分和相位，以优化所需的进步，并缺乏（3）对基础的理解，并且缺乏基础的理解。这项职业建议的目的是通过去除较小的贵族组件（例如将PDBI2转换为pd3bi，或Cuzn4转换为Cu5Zn8），从而在环境温度和压力下在环境温度和压力下在周围温度和压力下更富有熔点oics的相转换在环境温度和压力下的相变相变。该项目的基本见解将使OIC纳米结构的合理发展用于应用技术相关性，并提高我们对电催化条件下材料稳定性的理解。为了了解电化学交易介导的相位转换过程的起源，PI将研究以下目标：（1）阐明熔化温度对大量扩散和晶格重组的作用。（2）开发用于脱离合金OIC的受控组成的合成方法。（3）通过原位光谱法阐明交易。通过这种电化学介导的相位转换过程制造的材料将作为Li-Metal电池的阳极进行评估，以证明合成方法的实用性。该提案的更广泛影响将鼓励代表性不足的少数族裔（URM）K-12学生和（不在）研究生通过参与外展计划来购买STEM的职业。由于代表性不足，URM学生无法访问STEM领域中的相关榜样。为了解决这个问题，霍尔博士将使自己可以参加非正式的“咖啡小时讨论”，以作为巴尔的摩地区URM学生（高中生，本科生和研究生）的心理和榜样。 Hall小组还将通过参加巴尔的摩小学（SABES）计划的STEM成就来与K-12年龄的URM学生合作，从事基于询问的科学项目。该奖项反映了NSF的法定任务，并被认为是通过基金会的知识分子优点和更广泛影响的审查标准来通过评估来通过评估来支持的。