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原位透射电子显微学前沿论坛学术报告通知
2019-11-04 10:40   审核人:

原位透射电子显微分析是目前材料分析研究领域的最前沿领域,相关技术对于提升研究水平,获取高水平科研成果至关重要。材料学院科教实践与材料分析创新中心特组织原位透射电子显微学前沿论坛,邀请中国科学院物理所苏东研究员、上海交通大学邬建波研究员与武汉大学郑赫教授三位原位透射电子显微分析领域的知名专家为我校师生介绍原位透射电子显微分析技术的前沿应用,欢迎广大师生积极参与交流。具体安排如下:

时间:2019.11.5(星期二),上午9:00-11:30;

地点:创新科技大楼B座1330

报告一:Phase Evolution and Interfacial Strain in Electrode Materials for Energy Storage

Dong Su

Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China.

Advanced (scanning) transmission electron microscopy ((S)TEM) techniques have been intensively applied to study the materials for energy storage.  With/Combining different TEM techniques (including in-situ TEM and diffraction, HAADF-STEM, and STEM-electron energy-loss spectroscopy (EELS)), researchers are able to probe local structural and chemical information of electrode materials, at a resolution of nanoscale. This talk will focus on my recent work on using in-situ and analytical TEM to characterize the conversion-reaction oxide material (Fe3O4) for electrode of lithium ion batteries [1-3], and Pt based nanocatalysts for proton exchange membrane fuel cell[4]. The dynamical process of the redox reaction of Fe3O4 revealed by in-situ TEM may help us to understand how reaction pathways affect the batteries’ kinetic properties. For Pt based electrocatalyst, the strain coupling at interfaces is highlighted for its crucial role in determining the catalytic activity.

Reference:

[1] Visualizing non-equilibrium lithiation of spinel oxide via in situ transmission electron eicroscopy, K. He, et al., Nature Communications, 7,11441 (2016)

[2] Strain coupling of conversion-type Fe3O4 thin film for lithium ion battery, S. Hwang, et al. Angewandte Chemie, 56,7813, (2017)

[3] Phase evolution of conversion-type electrode for lithium ion batteries, J. Li, et al. Nature Communications, 10,2224 (2019)

[4] Biaxially strained PtPb/Pt core/shell nanoplate boosts oxygen reduction catalysis, Bu et al., Science, 354, 1410(2016)

 

报告人介绍:

Dr. Dong Su is a Professor at Institute of Physics (IOP), Chinese Academy of Sciences (CAS). Before joining IOP, he was the group leader of electron microscopy in Center for Functional Nanomaterials at Bookhaven National Laboratory until August 2019. He is also an adjunct professor in the Department of Materials Science and Engineering at Stony Brook University since 2011.  He got his B.S. in 1998 from Nanjing university. He got his Ph.D  in condensed matter physics in 2003, from Nanjing university and IOP, CAS. After doing postdoc in EPFL, Switzerland, University of Illinois at Urbana-Champaign, and Arizona State University, he joined Brookhaven National Laboratory in 2008 as an assistant scientist. He has been through the rank and was promoted to scientist with continuing appointment in 2015.   Dr. Dong Su has published more than 300 papers in peer-reviewed journals with citation >18,000(Google, H factor ~63). His work have been highlighted multiple times in public media and Department of Energy (DOE) website, including one of the 40 research milestones in DOE 40th anniversary. He has been a reviewer for DOE, NSF, and ACS grants and journals of Nature, Nature Materials, Nature Communications, Science Advances, PRL, JACS, etc, and an organizer of symposiums in national conferences and workshops. He has given more than 30 invited talks in international conferences and university seminars.            

报告二:高活性、低成本、长寿命燃料电池催化剂:从原位表征到材料设计

邬剑波

上海交通大学材料科学和工程学院,上海,中国,200240

*jianbowu@sjtu.edu.cn

多种形貌的多元金属核壳纳米结构因为其通过控制合金元素的分布表现出多重的功能引起极大的兴趣。许多年来,已经发展了多种气相和液相的手段合成这种核壳纳米结构, 其中形核生长的机理主要可归纳为层状生长、岛状生长和两者结合的这三种生长模式。最近,在透射电子显微技术上的一个重大发展是利用特殊的液体样品腔来对液相环境进行成像。这个液相成像技术上的突破提供了一种原位研究纳米晶形核生长行为的途径1-2。然而,其中一个重要挑战是如何能观察壳层材料在籽晶上的异质形核生长的全过程。我们通过利用微流体系统把前驱体溶液在透射电镜观察过程中注入到样品腔,使颗粒形核生长,从而能观察到整个核壳结构的形核过程3。我们通过对金在铂正二十面纳米颗粒的形核生长行为的原位研究,发现一种不同于上述三种生长行为的岛状沉积-表面扩散-层状生长的全新复合生长机制。这个对整个沉积生长过程的原位观察揭示了在生长过程中同时存在岛状生长和层状生长,其中的层状生长是通过沉积和表面扩散这两种生长模式达到的动态平衡。并根据上述的扩散理论开发出液相原子层沉积技术4-9。后续利用液相原位样品杆在透射电镜中研究20nm颗粒,特别在具有棱、角、面等多种三维几何位置的腐蚀行为。实验结果揭示了腐蚀速率先发生在立方体颗粒和二十面体颗粒的棱和角上,同时在(111)和(100)晶面上的腐蚀速度存在差异,并建立了动态腐蚀模型,提供一套利用TEM成像的二维形貌图片来研究纳米颗粒三维立体腐蚀行为,特别是三维空间下角、棱和面不同腐蚀模式的方法学,并且定量地计算微观不同取向的腐蚀速率10。通过对表面缺陷的原子层厚度的钯@铂方块的原位液相腐蚀过程的研究,发现表面缺陷控制是提高这类核壳结构催化剂稳定性的关键11。

参考文献

[1] H. Zheng, R. K. Smith, Y.-W. Jun, C. Kisielowski, U. Dahmen, A. P. Alivisatos; Science 2009, 324, 1309-1312.

[2] J. Wu,* H. Shan, W. Chen, X. Gu, P. Tao, C. Song, W. Shang, T. Deng,* Advanced Materials, 2016, 28, 9686-9712.

[3] J. Wu, W. P. Gao, J. G. Wen, D. J. Miller, P. Lu, J. M. Zuo, H. Yang, Nano Letters. 2015, 15, 2711-2715.

[4] T. Bian, H.Zhang*, Y. Jiang, C., J. Wu*, H. Yang*, D. Yang, Nano Letters, 2015, 15, 7808-7815.

[5] Y. Yan, H. Shan, G. Li, F. Xiao, Y. Jiang, Y. Yan, C. Jin, H. Zhang*, J. Wu*, D. Yang*, Nano Letters, 2016, 16, 7999-8004.

[6] Y. Xiong,† H. Shan,† Z. Zhou,† Y. Yan, Y. Liu, H. Tian,* J. Wu,* H. Zhang,* D. Yang, Small, 2017, 13, 1603423

[7] Y. Ma, W. Gao, H. Shan, W. Chen, W. Shang, P. Tao, C. Song, C. Addiego, T. Deng, X. Pan*, J. Wu* Advanced Materials, 2017, 29, 1703460.

[8] W. Chen,† W. Gao,† P. Tu, T. Robert, Y. Ma, H. Shan, X. Gu, W. Shang, P. Tao, C. Song, T. Deng, H. Zhu,* X. Pan,* H.Yang, J. Wu*, Nano Letters, 2018, 18, 5905-5912

[9] W. Gao, P. Tieu, C. Addiego, Y. Ma, J. Wu*, X. Pan*, Science Advances, 2019, 1, eaau9590.

[10] J. Wu, W. Gao, H. Yang, J. Zuo, ACS Nano, 2017, 11, 1696–1703.

[11] H Shan, W. Gao, Y. Xiong, F. Shi, Y. Yan, Y. Ma, W. Shang, P. Tao, C. Song, T. Deng, H. Zhang, D. Yang, X. Pan, J. Wu, Nat. Commun. 2018, 9, 1011.

报告人介绍:

邬建波,上海交通大学特别研究员、博士生导师、中央组织部青年千人。2014年12月加入上海交通大学材料科学与工程学院及金属基复合材料国家重点实验室,主要从事于贵金属材料成分结构设计与制备,复合与杂化,以及在催化和能源、微量探测、等离子共振、环境污染和水处理、生物医药等方面的应用研究。尤其专注于表面化学催化反应相关的表面结构和成分的控制,特别是对燃料电池中氧气的电催化还原反应的研究。近年来,利用原位环境电镜来研究催化剂的生长和在反应中的演变动力学过程。承担/参与国家科技部重点研发项目、国家自然科学基金委创新研究群体科学基金项目、国际(地区)合作与交流项目、面上项目等多项国家项目。在世界顶级杂志,包括Nat. Energy, Nat. Commun., Sci. Adv., Adv. Mater., Energy Environ. Sci., Chem. Soc. Rev., Acc. Chem. Res., J. Am. Chem. Soc., Nano Lett., ACS Nano, ACS Energy Lett.等发表100余篇高水平论文,引用达5300多次,H因子为34。影响因子 > 10 的论文有 30篇,拥有了6项国内国际专利及专利申请。

报告三:金属氧化物原子尺度界面及动态演变

郑赫

金属氧化物独特的物理、化学性能与缺陷息息相关。在样品制备过程中不可避免会引入氧空位、晶界等缺陷。课题组首先利用(球差校正)透射电子显微技术针对在能源存储及环境净化方面有重要应用的金属氧化物(例如ZnO/CuO等)的缺陷特别是原子尺度界面结构进行系统表征,通过实时观察其动力学生长过程,探讨其结构及性能的可能调控。随后,针对金属氧化物在实际服役条件下(应力场、电场或热场作用下)缺陷及晶界的原子尺度动态演变进行深入研究,揭示了低维尺度下金属氧化物特有的力学行为。研究结果为金属氧化物构效关系的搭建及应用设计提供借鉴

报告人介绍:

郑赫,博士生导师,武汉大学珞珈青年学者,武汉大学电镜中心副主任。长期从事固体材料超微结构表征的研究工作,利用先进的球差校正及原位电子显微技术,并结合第一性原理计算针对能源转化与存储领域有重要应用的微纳尺度材料结构缺陷的原子尺度表征、演变及调控开展系统深入的研究。在Nature Communications、Physical Review Letters、Physical Review Materials、Nano Letters等期刊上发表SCI论文60余篇,他引2000余次。

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