CAREER: Ultrafast Dynamics of Vibrational Energy Transfer and Redistribution in Interfacial Water

在化学系化学结构、动力学和机理A （CSDM-A）项目的支持下，加州州立大学的Abdelaziz Boulesbaa正在使用复杂的时间分辨激光光谱来研究液固界面处的水。研究这个界面带来了巨大的挑战，因为它只有一两个分子层厚，而且对于许多实验探针来说，来自水界面层的信号可能被液体中更多的分子淹没。Boulesbaa博士和他的学生将利用界面的能力，将光的颜色组合成新的颜色，这些颜色只来自与固体材料相邻的薄层水分子，以观察水分子之间的能量流动，时间尺度小于十亿分之一秒的千分之一。他们的发现可能会让我们更好地理解支撑新兴能源生产和存储技术的基本过程。该项目还将通过为研究生和本科生以及大洛杉矶地区社区学院的学生提供研究机会，为美国STEM（科学、技术、工程和数学）劳动力的发展做出贡献，这些学生将通过暑期实习参与该项目。该项目将实施一项协同研究和教育计划，旨在了解液态水和金属-半导体混合材料（MSH）界面上振动能量再分配和电荷转移的动力学和机制。时间分辨振动和频率产生（tr-vSFG）将用于观察在靠近MSH界面的水中泛音激发后的振动能量传递动力学，作为离子强度和液相pH的函数。电荷载流子从光激发MSH材料转移到液体及其随后的弛豫和反应性也将被研究。参与该项目的学生将学习先进的激光光谱技术，包括非线性光学，为未来在学术界或工业界的职业生涯做好准备。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。

With support from the Chemical Structure, Dynamics, and Mechanisms A (CSDM-A) program in the Division of Chemistry, Abdelaziz Boulesbaa of California State University, Northridge is using sophisticated time-resolved laser spectroscopies to study water at the liquid-solid interface. Studying this interface presents significant challenges because it is only one or two molecular layers thick, and for many experimental probes, the signal from the interfacial layer of water can be drowned out by the many more molecules in the liquid. Dr. Boulesbaa and his students will use the ability of the interface to combine colors of light into new colors, which originate only from the thin layer of water molecules neighboring the solid material, to watch the flow of energy between water molecules on time scales shorter than one thousandth of one billionth of a second. Their discoveries could lead to a better understanding of the fundamental processes underpinning emerging energy generation and storage technologies. The project will also contribute to the development of the Nation's STEM (science, technology, engineering and mathematics) workforce by providing research opportunities for graduate and undergraduate students, as well as students from community colleges in the greater Los Angeles area, who will participate in the project through summer internships. This project will implement a synergistic program of research and education directed at understanding the dynamics and mechanisms of vibrational energy redistribution and charge transfer at the interface between liquid water and metal-semiconductor hybrid (MSH) materials. Time-resolved vibrational sum-frequency generation (tr-vSFG) will be used to observe vibrational energy transfer dynamics following overtone excitation in water near the MSH interface as a function of the ionic strength and pH of the liquid phase. The transfer of charge carriers from the photoexcited MSH material into the liquid and their subsequent relaxation and reactivity will also be studied. Students who participate in this project will learn advanced laser spectroscopy techniques, including non-linear optics, an excellent preparation for future careers in academia or industry.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.