Li Jianfeng, Cheng Jun, Professor of Xiamen University: great breakthrough in the study of the configuration of water molecules on the solid-liquid interface

Professor Li Jianfeng and Professor Cheng Jun of the school of chemistry and chemical engineering of Xiamen University have made great breakthroughs in the study of the configuration of water molecules on the solid-liquid interface Relevant research results "in situ probing electrically interactive water structures at atomically flat surfaces" published nature materials (DOI: 10.1038 / s41563-019-0356-x) online Water is everywhere in nature People have been studying water molecules for more than a century Especially on the surface of materials, understanding the various physical and chemical processes of interface water from the atomic structure level will help to guide the development of better technologies and devices in the field of energy and environment Especially in electrochemistry, the detailed structure of interface water, such as its orientation in the double layer and the complex hydrogen bond network, has a significant impact on the electrochemical performance of electrode materials The vibrational spectra have been used to deduce the different configurations of water at the metal interface, such as four coordinated water, three coordinated water, surface characteristic adsorbed water, free water, etc However, there is still a lack of clear configuration images of these interface water at different potentials It is of great significance for the study of the electrochemical energy interface to detect the structure related activity and the mechanism of the interface reaction on the flat surface of the single crystal at the atomic level Using the surface enhanced Raman spectrum without the interference of the acceptor phase water, Professor Li Jianfeng's research group has obtained the Raman signal of the interface water on the surface of the gold (111) and (100) single crystal electrodes for the first time, and observed the two kinds of configuration transformation of the interface water in situ during the hydrogen evolution reaction It is found that the interface water changes from "parallel" structure to "single ended hydrogen downward" and then to "double ended hydrogen downward" with the negative shift of potential Using ab initio molecular dynamics theory, Professor Cheng Jun's research group simulated three configurations of interface water and corresponding number of hydrogen bonds in the double electric layer under different potentials, which were in good agreement with the experimental data, further revealing the atomic level structure of the double electric layer For the first time, the structure transformation of the interface water and the hydrogen bond fracture are correlated with the accurate electrode potential scale in the experimental and theoretical level, which is of guiding significance for the exploration of the three-dimensional structure of the double electric layer The research work was completed through cooperation within Xiamen University Professor Li Jianfeng and Professor Cheng Jun of the school of chemistry and chemical engineering provided important guidance for the corresponding author, Professor Tian Zhongqun Dr Li Chaoyu (now postdoctoral of MIT) and Dr Le Jiabo (now postdoctoral of collaborative innovation center of Energy Materials Chemistry) are the co first authors Dr Wang Yaohui provided help in the experiment Dr Chen Shu and Prof Yang Zhilin from the Department of physics carried out the electromagnetic field enhancement calculation for this work This work was greatly supported by NSFC (project approval No.: 21373166, 21775127, 2186112015, 21522508, 21521004, 21427813, 21321062, 21621091, 21533006), and supported by State Key Laboratory of solid surface physical chemistry, Key Laboratory of spectral credit analysis and instrument Education Ministry, and collaborative innovation center of energy and material chemistry.