Exploring the Unique Electrochemical Reactivity of Metallic Nanoparticles Less Than 4 nm in Diameter

探索直径小于4 nm的金属纳米颗粒独特的电化学反应性

• 批准号: 1308763
• 负责人: Francis Zamborini
• 金额: $ 39万
• 依托单位: University of Louisville Research Foundation Inc
• 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: 2013-09-15 至 2016-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1308763&HistoricalAwards=false
• 关键词: Exploring; Unique; Electrochemical; Reactivity; Metallic

Francis P. Zamborini from the University of Louisville is supported by the Macromolecular, Supramolecular and Nanochemistry program to explore the unique electrochemical reactivity of metal nanoparticles, focusing on oxidation and galvanic displacement reactions for those with diameters below 4 nm. The team has shown that there is a negative shift in oxidation potential for Au nanoparticles with decreasing size from diameters of 250 nm to 4 nm. The shift increases significantly below 4 nm. A goal of the work is to characterize the specific shift in oxidation potential for Au nanoparticles ranging from 250 nm down to 1 nm in diameter. A combination of mass spectrometry and electrochemical methods is being used to correlate the exact nanoparticle/cluster size with the oxidation potential. This provides important fundamental information about the stability of metal nanoparticles against oxidation as a function of size and a new electrochemical method for characterizing the size of metal nanoparticles. They have discovered that the oxidation of small metal nanoparticles also depends on the electrode material, the method of attachment to the electrode, their aggregation state, and the ligands used to assist in their oxidation. They are exploring these parameters systematically in order to gain a full understanding of all of the factors affecting metal nanoparticle oxidation. Galvanic displacement is an electrochemical reaction involving the replacement of one metal with another metal, which has been used to form interesting alloys, but has not been fully studied as a function of size. This reaction is also being explored with nanoparticles of varied size and focusing on those below 4 nm. Since the oxidation behavior changes dramatically below 4 nm, it is expected that the galvanic displacement reaction will show unique reactivity in this size regime, allowing for nanoparticle transformations and alloy formation not possible with larger sizes. The exploration of the oxidation and galvanic displacement of very small metal nanoparticles will lead to the discovery of new chemistry, synthesis of unique metal nanomaterials, and development of a new method of metal nanoparticle characterization.This project has broad significance and importance in many ways. In terms of the impact on the scientific community, this research is relevant to the discovery of new chemistry involving small metal nanoparticles, a new method for characterizing the size of metal nanoparticles, and new methods of synthesizing unique metal alloy nanomaterials. It also provides important fundamental information about metal nanoparticle stability, which is crucial for the numerous potential applications in medicine, chemical analysis, and energy. It further provides significant, multidisciplinary training of students of all levels, including high school, undergraduate, graduate, and post-graduate students. The results of this research are being incorporated into the undergraduate chemistry curriculum to educate students about the important size-dependent properties of materials, which is at the heart of nanotechnology research. This information is being made available to other educational institutions for broader dissemination. A one-day symposium is being hosted dedicated to women in science, with an emphasis on biotechnology and nanotechnology research. This includes participation from middle school students up to science professionals, including poster and oral presentations and a keynote lecture from a prominent female scientist. The program is being publicized to broaden the impact.

路易斯维尔大学的弗朗西斯·桑伯里尼（Francis P. Zamborini）得到了大分子，超分子和纳米化学计划的支持，探索金属纳米颗粒的独特电化学反应性，重点是氧化和电镀锌反应，这些反应均低于4 nm。 该小组表明，Au纳米颗粒的氧化潜力有负变化，其大小从直径降低到250 nm到4 nm。 偏移明显低于4 nm。 这项工作的目的是表征氧化潜力的特定转移纳米颗粒的直径范围从250 nm到1 nm。 质谱和电化学方法的组合被用来将确切的纳米颗粒/簇大小与氧化潜力相关联。 这提供了有关金属纳米颗粒对氧化的稳定性的重要基本信息，这是大小的函数以及一种表征金属纳米颗粒尺寸的新电化学方法。 他们发现，小型金属纳米颗粒的氧化也取决于电极材料，固定在电极上的方法，其聚集状态以及用于有助于其氧化的配体。 他们正在系统地探索这些参数，以便对影响金属纳米颗粒氧化的所有因素充分理解。 电流位移是一种电化学反应，涉及将一种金属替换为另一种金属，该金属已被用来形成有趣的合金，但尚未根据大小的函数进行全面研究。 该反应还通过不同大小的纳米颗粒进行探索，并专注于低于4 nm的纳米颗粒。 由于氧化行为在4 nm以下急剧变化，因此预计电流位移反应将在这种尺寸状态下显示出独特的反应性，从而使纳米颗粒的转换和合金形成不可能具有较大尺寸。 探索非常小的金属纳米颗粒的氧化和电流位移将导致发现新的化学反应，综合独特的金属纳米材料以及开发一种新的金属纳米颗粒表征的新方法。该项目在许多方面具有广泛的意义和重要性。 就对科学界的影响而言，这项研究与发现涉及小金属纳米颗粒的新化学反应有关，一种用于表征金属纳米颗粒大小的新方法以及合成独特金属合金纳米材料的新方法。 它还提供了有关金属纳米颗粒稳定性的重要基本信息，这对于医学，化学分析和能量的众多潜在应用至关重要。 它进一步为包括高中，本科，研究生和研究生在内的各个级别的学生提供了重要的多学科培训。 这项研究的结果已纳入本科化学课程中，以教育学生有关材料的重要尺寸依赖性特性，这是纳米技术研究的核心。 该信息已提供给其他教育机构以进行更广泛的传播。 为期一天的研讨会被献给了科学女性，重点是生物技术和纳米技术研究。 这包括从中学生到科学专业人士的参与，包括海报和口头演讲以及来自著名女科学家的主题演讲。 该计划正在宣传以扩大影响。