Seed-mediated co-reduction: a versatile route to architecturally-controlled bimetallic nanostructures

种子介导的共还原：结构控制双金属纳米结构的通用途径

• 批准号: 1306853
• 负责人: Sara Skrabalak
• 金额: $ 40.5万
• 依托单位: Indiana University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-05-15 至 2016-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1306853&HistoricalAwards=false
• 关键词: Seed; mediated; co; reduction; versatile

Sara Skrabalak from Indiana University is supported by the Macromolecular, Supramolecular and Nanochemistry Program in the Division of Chemistry to conduct research into rational syntheses and characterization of bimetallic nanoparticles with high structural monodispersity. Like their monometallic counterparts, bimetallic materials often display dramatic changes in their physicochemical properties at the nanoscale. To realize the full potential of bimetallic nanostructures, samples with structural monodispersity on-par with the best monometallic examples are needed; however, it remains a grand challenge to achieve structural and compositional control during the synthesis of bimetallic nanostructures. This challenge arises from reliance on co-reduction techniques to nucleate and grow a defined bimetallic phase, but the Skrabalak laboratory has demonstrated seed-mediated co-reduction as a strategy to overcome the limitations of co-reduction techniques by coupling them with the advantages of seeded methods which provide structurally defined crystals for bimetallic deposition. The aims of this project are i) to identify the synthetic parameters which govern morphology development during seed-mediated co-reduction and quantify their effects on the kinetics of co-reduction and crystal growth, ii) to identify the symmetry relationships between seed structure and the final morphologies of branched bimetallic nanocrystals prepared by seed-mediated co-reduction and quantify the effect of lattice mismatch between seed and overgrowth metals to morphology development, and iii) to identify the synthetic conditions which enable seed-catalyzed co-reduction of metal precursors and quantify the kinetics of this surface-mediated process via in situ synchrotron X-ray diffraction techniques. Collectively, the experiments being carried out are to identify and quantify the synthetic parameters which contribute to morphology development during seed-mediated co-reduction and enable new architecturally-controlled bimetallic nanostructures to be achieved. Additionally, the optical and catalytic properties of the unique nanostructures synthesized are being studied to understand how composition and architecture compound to impart new functionality. General design criteria for the synthesis of new bimetallic nanoarchitectures by seed-mediated co-reduction are being pursued, as well as the advancement of co-reduction techniques in general.Bimetallic nanostructures represent exciting multifunctional platforms with the potential to address critical needs in catalysis (e.g., in fuel cells), energy sustainability, chemical sensing, medicine, and beyond. However, predictably achieving architecturally-controlled bimetallic nanostructures has met with only modest success on account of the limitations of current synthetic strategies. This project is to obtain general design criteria for new bimetallic nanostructures and to move the nanosynthesis community closer to the predictive, on-demand synthesis of nanostructures with defined composition and architectures. This research also has the broader impacts of i) forging links between scientific disciplines that include nano/inorganic/solid-state chemistry and colloidal/surface/material sciences, ii) enhancing graduate/undergraduate education through multidisciplinary research and outreach activities that reinforce learning via teaching, iii) introducing nanoscale concepts to non-scientists and connecting undergraduates to their home communities through their research activities; iv) enabling the PI to serve the scientific community as an educator, journal and grant reviewer, and promoter of diversity in higher education; and v) generating and distributing new knowledge based on the proposed research through peer-reviewed publications and presentations.

来自印第安纳大学的 Sara Skrabalak 在化学系高分子、超分子和纳米化学项目的支持下，对具有高结构单分散性的双金属纳米粒子的合理合成和表征进行研究。 与单金属材料一样，双金属材料通常在纳米尺度上表现出物理化学性质的巨大变化。为了充分发挥双金属纳米结构的潜力，需要具有与最佳单金属示例相当的结构单分散性的样品；然而，在双金属纳米结构的合成过程中实现结构和成分控制仍然是一个巨大的挑战。这一挑战源于依赖共还原技术来成核和生长确定的双金属相，但 Skrabalak 实验室已经证明种子介导的共还原是一种克服共还原技术局限性的策略，通过将它们与以下优点结合起来：为双金属沉积提供结构明确的晶体的晶种方法。该项目的目的是 i) 确定在种子介导的共还原过程中控制形态发育的合成参数，并量化它们对共还原和晶体生长动力学的影响，ii) 确定种子结构和晶体生长之间的对称关系通过种子介导的共还原制备的支化双金属纳米晶体的最终形态，并量化种子和过度生长金属之间的晶格失配对形态发展的影响，以及iii)确定能够实现的合成条件金属前体的种子催化共还原，并通过原位同步加速器 X 射线衍射技术量化这种表面介导过程的动力学。总的来说，正在进行的实验是为了识别和量化合成参数，这些参数有助于种子介导的共还原过程中形态的发展，并能够实现新的结构控制的双金属纳米结构。此外，正在研究合成的独特纳米结构的光学和催化特性，以了解成分和结构化合物如何赋予新功能。人们正在寻求通过种子介导的共还原合成新型双金属纳米结构的通用设计标准，以及共还原技术的总体进步。双金属纳米结构代表了令人兴奋的多功能平台，有可能满足催化方面的关键需求（例如，燃料电池）、能源可持续性、化学传感、医学等。然而，由于当前合成策略的局限性，可预见地实现结构控制的双金属纳米结构仅取得了有限的成功。该项目旨在获得新型双金属纳米结构的通用设计标准，并使纳米合成界更接近于具有确定的成分和结构的纳米结构的预测性、按需合成。这项研究还具有更广泛的影响：i) 在包括纳米/无机/固态化学和胶体/表面/材料科学在内的科学学科之间建立联系，ii) 通过多学科研究和外展活动加强研究生/本科生教育，这些活动通过以下方式加强学习：教学，iii) 向非科学家介绍纳米级概念，并通过研究活动将本科生与其家乡社区联系起来； iv) 使 PI 能够作为教育者、期刊和拨款评审员以及高等教育多样性的推动者为科学界服务； v) 通过同行评审的出版物和演示，根据拟议的研究产生和传播新知识。