Kejun Liu
Professor
Academic Experience:
2024/04-presentInstitute of Functional Nano & Soft Materials, Soochow University, Distinguished Professor
2023/09 - 2024/04Max Planck Institute for Polymer Research, Department of Molecular Spectroscopy, Postdoctoral Researcher,
2022/09 - 2023/08University of Bern, Femtosecond Spectroscopy of Organic Materials Lab, Postdoctoral Researcher
2021/11 - 2022/08Max Planck Institute for Microstructure Physics, Department of Synthetic Materials and Functional Devices, Postdoctoral Researcher
2020/10 - 2021/10Dresden University of Technology, Laboratory for Molecular Functional Materials, Postdoctoral Researcher
2015/03 - 2020/10Dresden University of Technology, Laboratory for Molecular Functional Materials, Doctorate, Advisor: Prof. Xinliang Feng
2014/10 - 2015/02University of Freiburg, Department of Experimental Polymer Physics, PhD Student/Visiting Scholar
2011/09 - 2014/06Sichuan University, Polymer School, Master's
2007/09 - 2011/06Sichuan University, Polymer School, Department of Polymer Processing, Undergraduate
E-mail: kjliu@suda.edu.cn
Research Group Homepage:https://web.suda.edu.cn/lkj/
Address: Room F101A, Building 910, Dushu Lake Campus, Soochow University
Research Focus:
Water, the most important liquid in nature, not only promotes efficient self-assembly of molecules under 2D confinement at the air-water or air-amphiphile interface but also exhibits significant catalytic activity. This enables some chemical reactions, which are difficult to achieve in bulk phase at the ambient condition, to occur. Our team is committed to interdisciplinary fundamental research to explore the unique chemical reactions at water interfaces. This is not only expected to drive the development of new materials but also provides an important interdisciplinary platform for biochemistry, materials science, and other related disciplines. Additionally, we focus on synthesizing two-dimensional polymers, two-dimensional organic covalent frameworks (COFs), two-dimensional metal-organic frameworks (MOFs), and conjugated polymers using this interfacial chemical approach, and apply time-resolved terahertz spectroscopy and transient absorption spectroscopy to study their properties and reaction mechanisms. Recent progress includes:
(1) Non-conjugated two-dimensional polymer interface synthesis—monolayer surfactant-assisted interface synthesis of various crystalline two-dimensional polymers and LB film technology synthesis of monolayer two-dimensional polyimides;
(2) Conjugated two-dimensional polymer synthesis—using two-dimensional polypyrrole as an example, forming two-dimensional assemblies from one-dimensional polypyrrole with protonated quinoid structures at the interface;
(3) High-efficiency charge transfer behavior of two-dimensional polymers—based on structurally ordered two-dimensional polymers, exploring high-efficiency charge transfer behavior in two-dimensional polymers through ultrafast spectroscopy.
In summary, high-quality samples were synthesized and prepared; the structure and performance of two-dimensional polymers were systematically studied; a new perspective and experimental methods for an in-depth understanding of water interface chemistry were provided, pushing the boundaries of structure-function exploration in two-dimensional polymers, which will contribute to the development of new high-performance electronic and optoelectronic devices. To date, 19 research papers have been published, with 7 papers as the first author in journals including Nat. Chem., Angew. Chem. Int. Ed., and Adv. Mater., and one European patent has been applied for and granted.
Cooperation and Exchange:Our research group maintains stable cooperation with numerous research groups both domestically and internationally, such as Dresden University of Technology (Professor Xinliang Feng), Max Planck Institute for Polymer Research (Professor Mischa Bonn), Utrecht University (Professor Wang Hai), Sichuan University, and China Academy of Engineering Physics.
Recruitment Directions:Our research group warmly welcomes students and colleagues interested in colloidal and interface chemistry, polymer chemistry, two-dimensional materials, and transient laser spectroscopy to join us. We recruit masters, doctoral students, and postdoctoral researchers with backgrounds in chemistry, materials, physics, and related fields. Interested students and colleagues are welcome to consult and exchange.
Selected Publication:
1. Liu, Kejun; Qi, Haoyuan; Dong, Renhao; Shivhare, Rishi; Addicoat, Matthew; Zhang, Tao; Sahabudeen, Hafeesudeen; Heine, Thomas; Mannsfeld, Stefan; Kaiser, Ute; Zheng, Zhikun; Feng, Xinliang. On-water surface synthesis of crystalline, few-layer two-dimensional polymers assisted by surfactant monolayers, Nat. Chem., 2019, 11(11): 994-1000.
2. Liu, Kejun; Li, Jiang; Qi, Haoyuan; Hambsch, Mike; Rawle, Jonathan; Vázquez, Adrián Romani; Nia, Ali Shaygan; Pashkin, Alexej; Schneider, Harald; Polozij, Miroslav. A two-dimensional polyimide-graphene heterostructure with ultra-fast interlayer charge transfer, Angew. Chem. Int. Ed., 2021, 60(25): 13859-13864.
3. Liu, Kejun; Rehault, Julien; Liang, Baokun; Hambsch, Mike; Zhang, Yingying; Seçkin, Sezer; Zhou, Yunxia; Shivhare, Rishi; Zhang, Peng; Polozij, Miroslav; König, Tobias A. F.; Qi, Haoyuan; Zhou, Shengqiang; Fery, Andreas; Mannsfeld, Stefan C. B.; Kaiser, Ute; Heine, Thomas; Banerji, Natalie; Dong, Renhao; Feng, Xinliang. A quasi-2D polypyrrole film with band-like transport behavior and high charge carrier mobility, Adv. Mater., 2023, 35(40): 2303288.
4. Liu, Kejun; Wang, Lihuan; Dong, Renhao. Two-dimensional conjugated polymer films via liquid-interface-assisted synthesis toward organic electronic devices, J. Mater. Chem. C, 2020, 8(31): 10696-10718.
5. Liu, Kejun; Pastukhova, Nadiia; Pavlica, Egon; Bratina, Gvido; Feng, Xinliang. Air-Water Interface-Assisted Synthesis and Charge Transport Characterization of Quasi-2D Polyacetylene Films with Enhanced Electron Mobility via Ring-Opening Polymerization of Pyrrole, 2024. arXiv:2404.05402.
6. Prasoon, Anupam; Yu, Xiaoqing; Hambsch, Mike; Bodesheim, David; Liu, Kejun; Zacarias, Angelica; Nguyen, Nguyen Ngan; Seki, Takakazu; Dianat, Aerzoo; Croy, Alexander; Cuniberti, Gianaurelio; Fontaine, Philippe; Nagata, Yuki; Mannsfeld, Stefan C. B.; Dong, Renhao; Bonn, Mischa; Feng, Xinliang. Site-selective chemical reactions by on-water surface sequential assembly, Nat. Commun., 2023, 14(1): 8313.
7. Seki, Takakazu; Yu, Xiaoqing; Zhang, Peng; Yu, Chun-Chieh; Liu, Kejun; Gunkel, Lucas; Dong, Renhao; Nagata, Yuki; Feng, Xinliang; Bonn, Mischa. Real-time study of on-water chemistry: Surfactant monolayer-assisted growth of a crystalline quasi-2D polymer, Chem, 2021, 7(10): 2758-2770.
8. Sahabudeen, Hafeesudeen; Qi, Haoyuan; Ballabio, Marco; Položij, Miroslav; Olthof, Selina; Shivhare, Rishi; Jing, Yu; Park, SangWook; Liu, Kejun; Zhang, Tao; Ma, Ji; Rellinghaus, Bernd; Mannsfeld, Stefan; Heine, Thomas; Bonn, Mischa; Novas, Enrique C; Zheng, Zhikun; Kaiser, Ute; Dong, Renhao; Feng, Xinliang. Highly crystalline and semiconducting imine-based two-dimensional polymers enabled by interfacial synthesis, Angew. Chem. Int. Ed., 2020, 132(15): 6084-6092.
Edited by Juan Yang