Nanofabricated Model Systems for Investigations of Plasmon Enhanced Reactions

用于研究等离激元增强反应的纳米制造模型系统

• 批准号: 2150158
• 负责人: Brian Willis
• 金额: $ 42.26万
• 依托单位: University of Connecticut
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-07-15 至 2025-06-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2150158&HistoricalAwards=false
• 关键词: Nanofabricated; Model; Systems; Investigations; Plasmon

Energy efficiency, sustainability, and climate change are critical issues for our society to ensure prosperity and welfare through economic growth that does not harm the environment. There is growing interest to use solar energy for sustainable chemical manufacturing processes to replace the use of fossil fuels that currently contribute to carbon dioxide emissions and climate change. New catalysts, energy and feedstock sources, and chemical processing engineering strategies are necessary to meet these objectives. For example, fundamental scientific research is required to develop new materials that can capture and convert sunlight into fuels and useful chemical products. This research project addresses this challenge through a systematic study of nanostructured materials that efficiently capture light by a quantum-mechanical phenomenon known as plasmon resonances, wherein the light falling on the nanostructures causes some of the electrons to oscillate in unison. The intense electrical field generated in this manner then can be used to break the strong chemical bonds of carbon dioxide, nitrogen, and water vapor to initiate the chain of chemical reactions required to convert these common atmospheric species into valuable chemical products in a completely decarbonized manner. Little is known, however, about the interplay between these plasmonic resonances and the chemical reactions as well as the roles nanodevice materials and geometry play in maximizing the efficiency of these systems – this is the knowledge gap to be addressed by this research project, one that will train undergraduate and graduate-level engineering students in developing the engineering technology needed to create solar-powered chemical processes.An experimental research program is proposed to investigate plasmon-enhanced photochemistry using a unique surface chemistry approach combined with nanofabrication. Surface plasmon resonances concentrate electromagnetic energy at the nanoscale and have numerous potential applications in solar energy, photocatalysis, and nanoscale sensing. Plasmons are collective charge oscillations of the electron gas that are stimulated by light, and modes can be made resonant at specific frequencies by the choice of materials and nanostructure design. Localized surface plasmon resonances greatly enhance the interaction of light with matter and lead to intense electric fields, generation of hot carriers, and localized heating, all of which can be useful for driving chemical reactions. Non-thermal contributions to reactive processes via hot carriers and enhanced electric fields are especially of interest since they may lead to reactivity at lower temperatures and offer a means of controlling reaction selectivity towards desired chemical product distributions. In this project, model chemical reactions will investigated using nanofabricated structures with tunable resonances and engineered hot spots to learn how to design efficient plasmonic photocatalysts. The intellectual merits of this project are to design experiments that combine features of nanofabrication and surface science to measure reaction rates under well-defined conditions, including integrated optical and temperature measurements. Project goals include measurement of non-thermal contributions to rates of reaction for different nanostructure designs and materials to improve the understanding of hot carrier chemistry. The overall hypothesis to be evaluated by the proposed work is that hot carrier chemistry can be made more efficient by engineering nanostructures with electromagnetic “hot spots” to increase rates of hot carrier generation.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.

能源效率、可持续性和气候变化是我们社会通过不损害环境的经济增长确保繁荣和福利的关键问题。人们越来越有兴趣将太阳能用于可持续的化学制造过程，以取代目前导致二氧化碳排放和气候变化的化石燃料的使用。新的催化剂、能源和原料来源以及化学加工工程策略是实现这些目标所必需的。例如，需要进行基础科学研究，以开发能够捕获阳光并将其转化为燃料和有用的化学产品的新材料。该研究项目通过对纳米结构材料的系统研究来解决这一挑战，该纳米结构材料通过称为等离子体共振的量子力学现象有效地捕获光，其中落在纳米结构上的光引起一些电子一致振荡。然后，以这种方式产生的强电场可用于打破二氧化碳、氮气和水蒸气的强化学键，以引发将这些常见的大气物种以完全脱碳的方式转化为有价值的化学产品所需的化学反应链。然而，人们对这些等离子体共振和化学反应之间的相互作用以及纳米器件材料和几何形状在最大限度地提高这些系统的效率方面所起的作用知之甚少-这是本研究项目要解决的知识差距，一个将培训本科生和研究生水平的工程专业学生开发所需的工程技术，以创造太阳能-动力化学过程。提出了一个实验研究计划，研究等离子体增强的光化学使用一个独特的表面化学方法结合纳米纤维。表面等离子体共振在纳米尺度上集中电磁能量，并且在太阳能、太阳能电池和纳米传感中具有许多潜在的应用。等离子体激元是由光激发的电子气的集体电荷振荡，并且可以通过选择材料和纳米结构设计使模式在特定频率下共振。局部表面等离子体共振极大地增强了光与物质的相互作用，并导致强电场，热载流子的产生和局部加热，所有这些都可以用于驱动化学反应。通过热载流子和增强的电场对反应过程的非热贡献特别令人感兴趣，因为它们可以导致在较低温度下的反应性，并提供控制反应选择性朝向所需化学产物分布的手段。在这个项目中，模型化学反应将使用具有可调共振和工程热点的纳米制造结构进行研究，以学习如何设计高效的等离子体光催化剂。该项目的智力优势在于设计实验，将纳米纤维和表面科学的联合收割机特征结合起来，在明确定义的条件下测量反应速率，包括集成光学和温度测量。项目目标包括测量不同纳米结构设计和材料对反应速率的非热贡献，以提高对热载流子化学的理解。这项研究的总体假设是，通过设计具有电磁“热点”的纳米结构来提高热载流子生成率，可以使热载流子化学更有效。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估来支持。