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

The University Corporation, Northridge, Northridge CA

Investigators

Abstract

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.