The 1st International Conference on Two-Dimensional Layered Materials Abstracts October 12-15, 2014 Zhejiang Hotel, Hangzhou, China THE 1st INTERNATIONAL CONFERENCE ON 2DMAT Graphene and Beyond: Attraction, Reality and Future Zhongfan Liu Center for Nanochemistry, Beijing Science and Engineering Center for Low Dimensional Carbon Materials, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China E-mail: [email protected] Stimulated by graphene research, two dimensional (2D) atomic crystals have attracted great attentions these days. As a new category of materials dimensionality, various intriguing properties are expected for new sciences, new materials and new devices. There is huge space for exploration with these 2D materials. One of the key challenges including graphene itself at the current stage is still the synthesis of high-quality targeted 2D atomic crystals, which would determine how far we can go along this direction. We have been making great efforts on the chemical vapor deposition growth of graphene and other 2D atomic crystals since 2008 following a general concept of processing engineering. By rationally designing the growth catalysts and the elementary steps in the growth process, we have been able to make a precise control of graphene layer number, stacking structures, doping, wrinkle structures and even bandgaps by hybridization with different 2D materials. The accumulated experiences have also been applied to the growth of MoS2, WS2, h-BN and etc. The sp2 carbon network of graphene is chemically very stable and hence it is a great challenge for its chemical doping and tailoring. We are also working with a photochemical approach for graphene chemistry, where the chemical scissors are the highly reactive radicals generated from photochemical processes. A number of examples are given, including photochlorination, photomethylation, photocatalytic oxidation and Janus chemistry. References: [1] W Yan, WY He, ZD Chu, MX Liu, L Meng, RF Dou, YF Zhang, ZF Liu, JC Nie, L He, Strain and curvature induced evolution of electronic band structures in twisted graphene bilayer, Nature Comm. 4, 2159-2165 (2013). [2] LM Zhang, JW Yu, MM Yang, Q Xie, HL Peng, ZF Liu, Janus graphene from asymmetric two-dimensional chemistry, Nature Comm. 4, 1443-1449 (2013). [3] K Yan, D Wu, HL Peng, L Jin, Q Fu, XH Bao, ZF Liu, Modulation-doped growth of mosaic graphene with single-crystalline p-n junctions for efficient photocurrent generation, Nature Comm. 3, 1280-1286 (2012). [4] BY Dai, L Fu, ZY Zou, M Wang, HT Xu, S Wang, ZF Liu, Rational design of a binary metal alloy for chemical vapor deposition growth of uniform single-layer graphene, Nature Comm. 2, 522-527 (2011). [5] K Yan, L Fu, HL Peng, ZF Liu, Designed CVD Growth of Graphene via Process Engineering, Acc. Chem. Res. 10, 2263-2274 (2013). Plenary Talks | 1 THE 1st INTERNATIONAL CONFERENCE ON 2DMAT Novel Properties of 2D Materials beyond Graphene Tony F. Heinz Columbia University, USA Plenary Talks | 2 THE 1st INTERNATIONAL CONFERENCE ON 2DMAT Electronic Properties of van der Waals Heterostructures of Graphene and Hexagonal Crystals Vladimir Falko Department of Physics, Lancaster University E-mail: [email protected] Plenary Talks | 3 THE 1st INTERNATIONAL CONFERENCE ON 2DMAT Graphene Materials for High-Performance Energy Storage Guangmin Zhou1, Xuyi Shan1, Zhong-Shuai Wu1, Feng Li1, Wencai Ren1, Hui-Ming Cheng1* 1Advanced Carbon Division, Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China E-mail: [email protected] Graphene has many excellent properties, such as high specific surface area, good chemical stability, high electrical and thermal conductivity, high mechanical properties, and excellent flexibility. So graphene and its composite materials are expected to be used in high-performance energy storage devices. Synergistic effects between graphene and electrode materials and the beneficial roles of graphene in composite electrodes are widely found. It is demonstrated that, when the composites are used as electrode materials for lithium storage, compared to their individual constituents, graphene composites with unique structures such as anchoring, wrapping, encapsulating, sandwiching, buffering, layering and mixing have a significant improvement in their electrochemical properties such as high capacity, high rate capability and excellent cycling stability. The roles of graphene are considered to form a conductive network, increase electron and lithium ion conductivity, and anchor and trap electrode materials, and their efficiency is dependent upon how strong the interaction between graphene and electrode materials is. Graphene can also be used in flexible batteries and Li-S batteries. By coating active materials on a three-dimensional interconnected graphene framework (GF) developed at our lab, an anode and cathode were made to assemble a thin, lightweight and flexible lithium ion battery. The battery has shown high rate capability and capacity, and can be repeatedly bent down to <5 mm without failure and degradation of its electrochemical performance. We also designed a unique sandwich structure with pure sulfur between two graphene membranes for a Li-S battery to trap polysulfides. One graphene membrane was used as a current collector with sulfur coated on it as the active material, and the other graphene membrane was coated on a commercial polymer separator. The battery shows significant improvement in cyclability and capacity, because the electrode with two graphene membranes can provide rapid ion and electron transport paths, accommodate sulfur volumetric expansion and store and reuse migrating polysulfides to alleviate the shuttling effect. The fabrication of large-scale graphene materials has already been demonstrated, therefore, it is not too far from graphene materials to be used commercially for high-efficiency energy storage. Plenary Talks | 4 THE 1st INTERNATIONAL CONFERENCE ON 2DMAT Publishing in Nature X Luke Fleet Associate Editor of Nature Physics, Nature Publishing Group Plenary Talks | 5 THE 1st INTERNATIONAL CONFERENCE ON 2DMAT Preparation of Graphene and Its Electronic Properties Yunqi Liu Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China E-mail: [email protected] Controllable preparation of graphene is a pre-requirement both for basic research and practical applications of graphene. Chemical vapor deposition on metal crystals is widely used in the synthesis of graphene films duo to its combination of high quality and in large-scale. On the other hand, research on electronic properties of graphene is one of the most important topics of graphene. In this presentation, I will report a few recent results [16] on preparation of graphene in a controllable manner, and studies on its electronic properties. References: [1] Jianyi Chen, Yunlong Guo, Lili Jiang, Zhiping Xu, Liping Huang, Yunzhou Xue, Dechao Geng, Bin Wu, Wenping Hu, Gui Yu, and Yunqi Liu, Adv. Mater. 26(9), 1348-1353 (2014). [2] Jianyi Chen, Yunlong Guo, Liping Huang, Yunzhou Xue, Dechao Geng, Hongtao Liu, Bin Wu, Gui Yu, Wenping Hu, Yunqi Liu and Daoben Zhu, Phil. Trans. R. Soc. A 372, 20130017 (2014). [3] Lifeng Wang, Bin Wu, Jisi Chen, Hongtao Liu, Pingan Hu, and Yunqi Liu, Adv. Mater. 26(10), 1559-1564 (2014). [4] Zheye Zhang, Fei Xiao, Jiangbo Xi, Tai Sun, Shuang Xiao, Hairong Wang, Shuai Wang and Yunqi Liu, Sci. Rep. 4, 4053 (2014). [5] Birong Luo, Bingyan Chen, Lan Meng, Dechao Geng, Hongtao Liu, Jie Xu, Zhiyong Zhang, Hantang Zhang, Lianmao Peng, Lin He, Wenping Hu, Yunqi Liu, and Gui Yu, Adv. Mater. 26(20), 3218-3224 (2014). [6] Dechao Geng, Birong Luo, Jie Xu, Yunlong Guo, Bin Wu, Wenping Hu, Yunqi Liu, and Gui Yu, Adv. Funct. Mater. 24(12), 1664-1670 (2014). Symposium A, October 13 | 6 THE 1st INTERNATIONAL CONFERENCE ON 2DMAT Self-Assembly of Chemically Modified Graphene for Electrochemical Applications Wenjing Yuan, Liang Huang, Gaoquan Shi Department of Chemistry, Tsinghua University, Beijing 100084, China Chemically modified graphene (CMG) has attracted a great deal of attention in recent years because of its unique two-dimensional structure, high electrical conductivity and electrochemical stability, excellent mechanical property and processibility. It has a variety of electrochemical applications in electrocatalysis, electrochemical sensors, actuators, and energy related systems. However, the sizes of CMG sheets are usually in the range of submicrometer to several micrometers. Furthermore, the restacking of graphene sheets usually greatly decreases the specific areas of electrode materials. The electrochemistry of graphene sheets have also not been revealed clearly. In this report, I will describe the self-assembly of CMG sheets for electrochemical purposes. The applications of CMGs in electrochemical biosensors, gas sensors, electrocatalysis, electrochemical actuators and electrochemical capacitors will be discussed. This work was supported by national basic research program of China (973 Program, 2012CB933402) and Natural Science Foundation of China. References: [1] W. J. Yuan, A. R. Liu, L. Huang, C. Li, G. Q. Shi, Adv. Mater. 25, 766 (2013). [2] C. Li, G. Q. Shi, Adv. Mater. 26, DOI: 10.1002/adma.201306104 (2014). [3] C. C. Huang, C. Li, G. Q. Shi, Energy & Environ. Sci. 5, 8848 (2012). Symposium A, October 13 | 7 THE 1st INTERNATIONAL CONFERENCE ON 2DMAT Macroscopic Assembled Graphene Chao Gao Zhejiang University, China Symposium A,