CAREER: Time-Resolved Studies of Charge Transfer and Chemical Reactivity at Photoelectrode-Electrolyte Interfaces

在这个由化学学部化学结构动力学和机制（CSDM-A）项目支持的项目中，饶毅博士和他在犹他州立大学（USU）的学生将开发复杂的激光技术，探索二氧化碳（CO2）在光电极-电解质界面转化为燃料的过程。界面是几个分子宽的薄区域，两种体相（如固体和液体）在这里相遇。在这种情况下，边界是在固体光电极和液体之间，固体光电极是可以发生光激活反应的表面，而液体则可以导电。这项研究提高了我们对由太阳能和电力驱动的界面上二氧化碳反应的认识。这项工作将整合科学训练和发现，使用基于激光的光谱工具作为其基石，以加强本科和研究生水平的教学。在教育背景下利用这一研究专长，Rao博士计划为K-12学生举办光子燃料研讨会，并在当地社区举办USU Science Unwrapped外展活动。本项目主要利用新开发的界面选择光谱工具，包括时间分辨电子和频率生成（TR-ESFG）和时间分辨振动和频率生成（TR-VSFG），研究光电极-电解质界面上的超快界面电荷转移和化学反应性。这些技术是Rao小组最近开发和建立的，为推进PEC减少二氧化碳和其他相关界面现象的基础知识提供了一个独特的机会。光电极-电解质界面上的光电化学反应的预期结果包括：(1)识别界面状态以及pH、离子种类、离子强度和应用电位的影响；(2)定量测定反应物和中间体的结合几何形状和强度；(3)建立界面状态和中间体之间的关系。这项工作的更广泛的社会影响是增加了对太阳能燃料界面化学反应性的理解。该项目还将使学生在尖端激光技术、电化学和材料科学方面获得宝贵的经验。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

In this project supported by the Chemical Structure Dynamics and Mechanisms (CSDM-A) program of the Chemistry Division, Dr. Yi Rao and his students at Utah State University (USU) will develop sophisticated laser techniques to explore conversion of carbon dioxide (CO2) into fuels at photoelectrode-electrolyte interfaces. Interfaces are thin regions-a few molecules wide-where two bulk phases, such as a solid and liquid, meet. In this case, the boundary is between a solid photoelectrode, a surface where a light-activated reaction can occur, and a liquid that can conduct electricity. The research is advancing our knowledge of reactions of CO2 at interfaces, driven by solar energy and electricity. The work will integrate scientific training and discovery, using laser-based spectroscopic tools as its cornerstone to enhance teaching at the undergraduate and graduate levels. Leveraging this research expertise in an educational context, Dr. Rao plans to facilitate PHOTON FUELS workshops for K-12 students and hosts USU Science Unwrapped outreach events in the local community. This project focuses on ultrafast interfacial charge transfer and chemical reactivity at the photoelectrode-electrolyte interfaces using newly developed interface-selective spectroscopic tools, including time-resolved electronic sum frequency generation (TR-ESFG) and time-resolved vibrational sum frequency generation (TR-VSFG). These techniques, recently developed and established in the Rao group, provide a unique opportunity to advance fundamental knowledge of the PEC reduction of CO2 and other related interfacial phenomena. The expected outcomes of photoelectrochemical reactions at the photoelectrode-electrolyte interfaces include (1) identification of interfacial states and the effect of pH, ionic species, ionic strength, and applied potentials, (2) quantification of binding geometry and strengths of reactants and intermediates, and (3) development of a relationship between interfacial states and intermediates. A broader societal impact of this work is increased understanding of interfacial chemical reactivity of solar fuels. The project also will allow students to gain valuable experience in cutting-edge laser technology, electrochemistry, and materials science.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.