Collaborative Research: Environmental Electron Doping of Iron Oxide Nanoparticles: Influence on Particle Properties and Reactivity

合作研究：氧化铁纳米粒子的环境电子掺杂：对粒子性质和反应性的影响

• 批准号: 1708513
• 负责人: Paul Tratnyek
• 金额: $ 14.96万
• 依托单位: Oregon Health & Science University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-08-01 至 2020-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1708513&HistoricalAwards=false
• 关键词: Collaborative; Research; Environmental; Electron; Doping

This award is funded jointly by the Environmental Chemical Sciences (ECS) Program in the Division of Chemistry and the Geobiology and Low Temp Geochemistry Program in the Division of Earth Sciences. Professor Scherer (University of Iowa, UI) and Professor Tratnyek (Oregon Health Sciences University) study the electrochemical behavior of iron oxides in soil and water. Iron oxides are found in virtually all surface environments on Earth, and have also been identified on the surface of Mars. These tiny, often nano-sized (1 billionth of a meter), particles are also major components of paints, steel, and batteries. Despite their environmental and technological relevance, the electrochemical behavior of iron oxides in the environment remains poorly understood. The goal of the project is to understand the behavior of iron oxide nanoparticles in water and soil. This understanding may help environmental chemists and engineers address important water quality issues such as arsenic in groundwater and develop alternative methods for low-cost, low-energy water treatment. This work aids in the protection of public health by advancing predictions of chemical exposure from surface and ground waters. It also provides important insights into how land use changes impact climate change, as carbon is often directly bound to iron oxides in soils. The graduate students at UI working on this research project are part of the NSF Research Traineeship (NRT) program in Sustainable Water Development. Professors Scherer and Tratnyek develop and lead educational outreach efforts to K-12 students and water treatment professionals. Professor Scherer uses LEGO Molecule Kits to develop hands-on activities for students to learn about environmental reactions and Professor Tratnyek workshops for technical training certification for wastewater and water operators at a local community college. The results from this research may help protect public health by providing new knowledge on how to minimize exposure to contaminants in water (e.g., arsenic, which is linked to iron oxide solubility) and manipulate iron availability to raise primary productivity of oceanic waters. It is well known that iron (Fe) oxides are semiconductors and that their properties and behavior can be altered significantly by introducing trace impurities, i.e., doping. It is, however, still unclear to what extent electron doping of iron oxides occurs in the natural environment. The goal of this project is to determine whether iron oxide nanoparticles can be doped with electrons from reaction with natural chemical species, such as ferrous iron and sulfide, and how doping alters iron oxide properties and reactivity. Advanced spectroscopic and electrochemical techniques are used to measure changes in electronic or magnetic particle properties, such as band gap and Mössbauer transition temperatures. In addition, a suite of electrochemical methods is used to measure the redox properties of the particles. The reactivity of electron doped nanoparticles is measured with respect to contaminant oxidation, contaminant reduction, and dissolution. in additional to possible impacts in the environment, this research may also provide new insights on the material properties of Fe oxide which can be used to develop innovative, cost-effective batteries for energy storage and conversion.

该奖项由化学部的环境化学科学（ECS）计划和地球科学部的地球生物学和低温地球化学计划共同资助。谢勒教授（爱荷华州大学，UI）和特拉特涅克教授（俄勒冈州健康科学大学）研究土壤和水中铁氧化物的电化学行为。氧化铁几乎存在于地球上所有的表面环境中，在火星表面也发现了氧化铁。这些微小的，通常是纳米尺寸（十亿分之一米）的颗粒也是油漆，钢铁和电池的主要成分。尽管其环境和技术相关性，铁氧化物在环境中的电化学行为仍然知之甚少。该项目的目标是了解氧化铁纳米颗粒在水和土壤中的行为。这种理解可能有助于环境化学家和工程师解决重要的水质问题，如地下水中的砷，并开发低成本，低能耗的水处理替代方法。这项工作通过促进对地表水和地下沃茨化学品接触的预测，有助于保护公众健康。它还提供了关于土地利用变化如何影响气候变化的重要见解，因为碳通常直接与土壤中的氧化铁结合。UI研究生在这个研究项目的工作是NSF研究培训（NRT）计划在可持续水发展的一部分。教授谢勒和Tratnyek开发和领导教育推广工作，以K-12学生和水处理专业人员。教授谢勒使用乐高分子套件开发动手活动，让学生了解环境反应和教授Tratnyek研讨会的技术培训认证的废水和水操作员在当地社区学院。这项研究的结果可能有助于保护公众健康，因为它提供了关于如何最大限度地减少接触水中污染物的新知识（例如，砷与氧化铁的溶解度有关），并控制铁的可用性，以提高海洋沃茨的初级生产力。众所周知，铁（Fe）氧化物是半导体，并且它们的性质和行为可以通过引入痕量杂质（即，兴奋剂然而，目前还不清楚在自然环境中铁氧化物的电子掺杂程度。该项目的目标是确定氧化铁纳米颗粒是否可以掺杂与天然化学物质（如亚铁和硫化物）反应的电子，以及掺杂如何改变氧化铁的性质和反应性。先进的光谱和电化学技术用于测量电子或磁性粒子特性的变化，如带隙和穆斯堡尔转变温度。此外，一套电化学方法被用来测量颗粒的氧化还原性能。电子掺杂的纳米颗粒的反应性测量相对于污染物氧化，污染物还原，和溶解。 除了可能对环境产生的影响外，这项研究还可能为氧化铁的材料特性提供新的见解，这些特性可用于开发创新的、具有成本效益的电池，用于能量存储和转换。