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

在加州州立大学Abdelaziz Boulesbaa化学系化学结构、动力学和机理A(CSDM-A)计划的支持下，北岭正在使用复杂的时间分辨激光光谱仪来研究液-固界面上的水。研究这种界面面临着巨大的挑战，因为它只有一两个分子层厚，对于许多实验探测器来说，来自水界面层的信号可能会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物质相邻的薄层水分子，他们将在不到十亿分之一秒的时间尺度上观察水分子之间的能量流动。他们的发现可能会让人们更好地理解支撑新兴能源发电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大学的学生提供研究机会，促进国家STEM(科学、技术、工程和数学)劳动力的发展，他们将通过暑期实习参与该项目。该项目将实施一个研究和教育的协同计划，旨在了解液态水和金属-半导体杂化(MSH)材料之间的振动能量重新分配和电荷转移的动力学和机制。时间分辨振动和频产生(tr-vSFG)将被用来观察泛音激发后MSH界面附近的水中振动能量传递动力学随离子强度和液态pH的变化。我们还将研究电荷载流子从光激发的MSH材料转移到液体中，以及它们随后的弛豫和反应活性。参与该项目的学生将学习先进的激光光谱学技术，包括非线性光学，为未来在学术界或行业的职业生涯做好准备。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.