Abstract:
Condensed matter interfaces, found both in nature and human-made devices (like the seabed, cell membranes, and electrodes), are critical for understanding energy and mass flow. However, investigating their molecular structures and dynamics is challenging. Techniques involving photons are preferred over those using electrons or ions due to the latter's limitations in condensed matter. Traditional optical spectroscopies (e.g., infrared, UV-vis absorption, Raman scattering) offer valuable insights into condensed matter's speciation and structure but fall short in interface sensitivity and selectivity. Sum Frequency Generation (SFG), a second-order nonlinear optical process, stands out for its interface sensitivity and ability to provide unique information about interfacial species' order, symmetry, and orientation. Utilizing femtosecond lasers with SFG can also reveal ultrafast dynamics, offering a deeper understanding of these interfaces.
In my presentation, I will discuss how SFG is crucial for investigating the symmetry, order and orientation of species at interfaces, drawing on my latest research1-5. I'll cover the mathematical principles of SFG's selection rule, interactions between light and materials, and energy relaxation dynamics. Finally, I will address SFG's limitations6, 7 and its future potential in studying electrified interfaces8.
(1) Yang, T.; Sleziona, S.; Pollmann, E.; Hasselbrink, E.; Kratzer, P.; Schleberger, M.; Kramer Campen, R.; Tong, Y. Phys. Rev. B 2024 in press; arXiv:2310.19657. DOI:10.48550/arXiv.2310.19657
(2) Yang, T.; Pollmann, E.; Sleziona, S.; Hasselbrink, E.; Kratzer, P.; Schleberger, M.; Campen, R. K.;Tong, Y. Phys. Rev. B 2023, 107 (15), 155433. DOI: 10.1103/PhysRevB.107.155433
(3) Yue, Y.; Melani, G.; Kirsch, H.; Paarmann, A.; Saalfrank, P.; Campen, R. K.; Tong, Y. J. Phys. Chem.C 2022, 126 (31), 13467-13476. DOI: 10.1021/acs.jpcc.2c03743
(4) Gong, X.; Campen, R. K.; Tong, Y. J. Phys. Chem. C 2023, 127 (33), 16615-16622. DOI:10.1021/acs.jpcc.3c03038
(5) Zhang, I. Y.; Zwaschka, G.; Wang, Z.; Wolf, M.; Campen, R. K.; Tong, Y.. Phys. Chem. Chem. Phys.2019, 21 (35), 19147-19152, 10.1039/C9CP03397A. DOI: 10.1039/C9CP03397A
(6) Lapointe, F.; Wolf, M.; Campen, R. K.; Tong, Y. J. Am. Chem. Soc. 2020, 142 (43), 18619-18627.DOI: 10.1021/jacs.0c08289
(7) Zwaschka, G.; Lapointe, F.; Campen, R. K.; Tong, Y. Curr. Opin. Electrochem. 2021, 29, 100813.DOI:10.1016/j.coelec.2021.100813
(8) Tong, Y. Linear vs. nonlinear electrochemical vibrational stark effect: Preconditions of the approximation. In Encyclopedia of Solid-Liquid Interfaces (First Edition), Wandelt, K., Bussetti, G. Eds.;Elsevier, 2024; pp 750-759. DOI:10.1016/B978-0-323-85669-0.00073-8
Short Introduction：
Dr. Yujin Tong graduated with a bachelor's (2003) and master's (2005) degree from Harbin Institute of Technology and completed his Ph.D. at Hokkaido University's Catalysis Research Center in Japan in 2010. He currently serves as a Senior Lecturer in the Physics Department at the University of Duisburg-Essen, Germany, and was the former groupleader of the " Nonlinear SpectroElectrochemistry Group " at the Fritz Haber Institute of the Max Planck Society. He has been the former president of the Chinese German Chemical Association (CGCA) from 2016 to 2018, a member of the International Society of Electrochemistry, the German Physical Society, and a member of the Ertl Center for Electrochemistry and Catalysis (named after the 2017 Nobel Laureate in Chemistry). Tong has dedicated years to the development and application of advanced surface science characterization methods, notably applying nonlinear laser spectroscopy techniques to the investigation of electrified solid/liquid interfaces, earning wide international recognition. As the first author or corresponding author, he has published over 60 research papers in leading international journals such as Nature Communications, Angewandte Chemie International Edition, and the Journal of the American Chemical Society. He has been invited to review grant proposals for the French National Research Agency (ANR) and to peer-review for prestigious journals including Nature series and journals of the American and German Chemical Societies. He frequently delivers keynotes at international conferences and actively organizes academic and technical exchanges between China and Germany.
Address：M253
Inviter：任新国（82649603)