This journal is © The Royal Society of Chemistry 2016 Chem. Soc. Rev. Cite this: DOI: 10.1039/c6cs00218h Three-dimensional macro-structures of two-dimensional nanomaterials Khurram Shehzad,† a Yang Xu,†* ab Chao Gao c and Xiangfeng Duan b If two-dimensional (2D) nanomaterials are ever to be utilized as components of practical, macroscopic devices on a large scale, there is a complementary need to controllably assemble these 2D building blocks into more sophisticated and hierarchical three-dimensional (3D) architectures. Such a capability is key to design and build complex, functional devices with tailored properties. This review provides a comprehensive overview of the various experimental strategies currently used to fabricate the 3D macro-structures of 2D nanomaterials. Additionally, various approaches for the decoration of the 3D macro-structures with organic molecules, polymers, and inorganic materials are reviewed. Finally, we discuss the applications of 3D macro-structures, especially in the areas of energy, environment, sensing, and electronics, and describe the existing challenges and the outlook for this fast emerging field. 1. Introduction The discovery of graphene just over one decade ago 1 completes the dimensionality spectrum of sp 2 bonded carbon materials, including zero-dimensional (0D) fullerenes, 2,3 one-dimensional (1D) nanotubes, 4,5 two-dimensional (2D) graphene, 6 and three- dimensional (3D) graphite 7 (Fig. 1). Ever since its first discovery, graphene has quickly become the central focus of research across multiple disciplines including chemistry, physics, materials science, a College of Information Science and Electronic Engineering and State Key Laboratory of Silicon Materials, Zhejiang University, Hangzhou, Zhejiang, 310027, China. E-mail: yangxu-isee@zju.edu.cn b Department of Chemistry and Biochemistry and California Nanosystems Institute, University of California, Los Angeles, California 90095, USA c MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Zhejiang University, Hangzhou 310027, China Khurram Shehzad Dr Khurram Shehzad received his MSc and MPhil in Chemistry from the University of the Punjab, Lahore, Pakistan, and PhD in Materials Science and Engineering from Beijing Univer- sity of Chemical Technology, Beijing, China. From 2011–2013, he was a Postdoctoral Research Fellow at the Center for Nano and Micro Mechanics, Tsinghua Uni- versity, Beijing, China. Currently, he is a Postdoctoral Fellow at the College of Information Science and Electronics, Zhejiang University, China. He is the recipient of several awards including the International Young Scientist Fellowship from NSF China, Nanchang University Fellowship, CAS President Fellowship, and the Cultural Exchange Fellowship. His current research interests include hetero-structures and the macro-assemblies of two-dimensional materials for their applica- tions in energy, healthcare, and electronics. Yang Xu Dr Yang Xu received his BS degree in ECE from Tsinghua University, Beijing, and MS and PhD degrees in ECE from the University of Illinois at Urbana and Champaign. He is a Fellow of Churchill college at the Univer- sity of Cambridge, UK, and a visiting professor at UCLA. He is now with the College of Infor- mation Science and Electronic Engineering, Zhejiang University, China. His current research interests include emerging low- dimensional smart sensors and actuators for the internet-of- things and flexible electronics. † Both authors have equal contribution. Received 16th March 2016 DOI: 10.1039/c6cs00218h www.rsc.org/chemsocrev Chem Soc Rev REVIEW ARTICLE Published on 27 July 2016. Downloaded by Zhejiang University on 09/10/2016 08:33:34. View Article Online View Journal