title: Ultrathin nickel hydroxide and oxide nanosheets: synthesis, characterizations and excellent supercapacitor performances.
abstract: High-quality ultrathin two-dimensional nanosheets of α-Ni(OH)2 are synthesized at large scale via microwave-assisted liquid-phase growth under low-temperature atmospheric conditions. After heat treatment, non-layered NiO nanosheets are obtained while maintaining their original frame structure. The well-defined and freestanding nanosheets exhibit a micron-sized planar area and ultrathin thickness (<2 nm), suggesting an ultrahigh surface atom ratio with unique surface and electronic structure. The ultrathin 2D nanostructure can make most atoms exposed outside with high activity thus facilitate the surface-dependent electrochemical reaction processes. The ultrathin α-Ni(OH)2 and NiO nanosheets exhibit enhanced supercapacitor performances. Particularly, the α-Ni(OH)2 nanosheets exhibit a maximum specific capacitance of 4172.5 F g(-1) at a current density of 1 A g(-1). Even at higher rate of 16 A g(-1), the specific capacitance is still maintained at 2680 F g(-1) with 98.5% retention after 2000 cycles. Even more important, we develop a facile and scalable method to produce high-quality ultrathin transition metal hydroxide and oxide nanosheets and make a possibility in commercial applications.
authors.affiliation: Research Center of Materials Science, Beijing Institute of Technology, Beijing 100081, China.
authors.forename: Youqi
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: Research Center of Materials Science, Beijing Institute of Technology, Beijing 100081, China.
authors.forename: Chuanbao
authors.initials: C
authors.lastname: Cao
authors.affiliation: National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029, China.
authors.forename: Shi
authors.initials: S
authors.lastname: Tao
authors.affiliation: National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029, China.
authors.forename: Wangsheng
authors.initials: W
authors.lastname: Chu
authors.affiliation: National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029, China.
authors.forename: Ziyu
authors.initials: Z
authors.lastname: Wu
authors.affiliation: Department of Chemistry, Tsinghua University, Beijing 100084, China.
authors.forename: Yadong
authors.initials: Y
authors.lastname: Li