报告题目：Atomic-resolution transmission electron microscopy of electron beam-sensitive crystalline materials

主讲嘉宾：Professor Yu Han（Kingdom of Saudi Arabia）

时　　间：6月29日（周四） 10：00-11：30

地　　点：李薰楼356会议室

报告简介

In the first part of this presentation, I will give a brief introduction to the research activities of my group, which center around the synthesis and applications of nanoporous and nanostructured materials.  In the second part, I will talk about our recent efforts on high-resolution imaging of electron beam-sensitive materials that is one of the most difficult applications of transmission electron microscopy (TEM). Specifically, we develop a suite of new methods to advance the high-resolution TEM imaging of extremely electron beam-sensitive materials from “impossible” to “routine”; We demonstrate the effectiveness of our methodology by capturing atomic-resolution TEM images of several metal organic frameworks (MOFs) that are generally recognized as highly sensitive to electron beams. In the case of MOF UiO-66, the high image resolution (~1.6 Å) allows us to clearly identify individual metal atomic columns, various types of surface termination, and benzene rings in the organic linkers. This is the first TEM image of benzene rings in organic molecules; We also successfully apply our methods to other electron beam-sensitive materials, and achieve atomic-resolution TEM imaging of the organic-inorganic hybrid perovskite CH3NH3PbBr3 for the first time.

主讲嘉宾简介

Dr Han is a materials chemist and his research is focused on nanoporous and nanostructured materials, including ordered mesoporous materials, hierarchically structured zeolites, porous organic polymers, porous carbons, and metallic plasmonic nanocrystals. His ability to precisely control the structure and morphology of these materials promoted his great success in developing novel applications for them in gas adsorption/separation, heterogeneous catalysis, and nanophotonics. Dr. Han also has expertise in electron microscopy and electron tomography, using which he has successfully solved or identified some complex nanostructures. Dr. Han has published > 160 journal articles, and these papers have been cited over 10000 times with h-index of 48. His achievements have garnered international recognition. In 2004, he was named as a TR100 Young Innovator by the Massachusetts Institute of Technology’s magazine of innovation, Technology Review. In 2006, he was awarded the Young Scientist Award by the Singapore National Academy of Science. In 2016, he got the Cheung Kong Scholar award, the highest academic award issued to an individual in higher education by the Ministry of Education of the People's Republic of China.