Peking University, Jan. 7, 2019: On January 7, 2019, “China/World's Top 10 Sci-tech Advancement News in 2018”, voted by members of the Chinese Academy of Sciences and Chinese Academy of Engineering, was announced in Beijing. The research “The First Disclosure of the Hydrated Ion Microstructure”, led by Professor Wang Enge and Professor Jiang Ying of International Center for Quantum Materials (ICQM) at Peking University, was selected. This is the second time that their research has been on the list of “China/World's Top 10 Sci-tech Advancement News” since 2016.
a-e. Atomically resolved images of sodium hydrate from left to right are: atomic geometry images, scanning tunneling microscopy (STM) images, atomic force microscopy (AFM) images and AFM simulation images respectively. The size of the figure is 1.5nm×1.5nm.
f. The magic number effect scheme of surface transportation of sodium hydrate on NaCl, indicating extraordinarily high diffusion of hydrate with three H2O molecules.
g. Mean-square displacements of different hydrated ions between 225 K and 300 K in 1 ns from molecular dynamic simulation.
The formation of hydrated ion between ion and water molecular is one of the most important and common effects in nature, and plays important roles in chemical, physical and biological processes. Since the end of 19 century, researchers have realized the existence of hydrated ions and started to study them. While the microscopic structure and dynamics of hydrated ions remain a research focus, a certain conclusion has been absent for more than 100 years. The challenge lies in the unavailability of accurate characterization instruments and reliable simulated calculation methods.
Wang and Jiang’s team cooperated with Xu Limei in ICQM and Gao Yiqin in the College of Chemistry and Molecular Engineering to develop a new STM technology based on high-order electrostatic force, which had the highest STM spatial resolution and achieved direct image and location for hydrogen atom. This is the first time to acquire atomic resolution image of single Na+ hydrated ion, and the researchers found that a certain number of water molecular could increase migration rate for several order of magnitudes, which is a new dynamic magic number effect. For the first time, this work clarified the atomic configuration of hydrated ion at the interface and established a direct correlation between the microstructure and transport properties of hydrated ion, changing the traditional understanding towards ion transport in restricted systems. This work has great potential for many applications such as ion batteries, desalination, and biological ion channels and was published on Nature on May 14, 2018. David Schilter, editor-in-chief of Nature Chemistry, highlighted this work and commended it “Perfect structure and dynamic information of hydrated ions”.
Written by: Qiu Tianjie
Edited by: Huang Weijian
