title: High-quality metal oxide core/shell nanowire arrays on conductive substrates for electrochemical energy storage.
abstract: The high performance of a pseudocapacitor electrode relies largely on a scrupulous design of nanoarchitectures and smart hybridization of bespoke active materials. We present a powerful two-step solution-based method for the fabrication of transition metal oxide core/shell nanostructure arrays on various conductive substrates. Demonstrated examples include Co(3)O(4) or ZnO nanowire core and NiO nanoflake shells with a hierarchical and porous morphology. The "oriented attachment" and "self-assembly" crystal growth mechanisms are proposed to explain the formation of the NiO nanoflake shell. Supercapacitor electrodes based on the Co(3)O(4)/NiO nanowire arrays on 3D macroporous nickel foam are thoroughly characterized. The electrodes exhibit a high specific capacitance of 853 F/g at 2 A/g after 6000 cycles and an excellent cycling stability, owing to the unique porous core/shell nanowire array architecture, and a rational combination of two electrochemically active materials. Our growth approach offers a new technique for the design and synthesis of transition metal oxide or hydroxide hierarchical nanoarrays that are promising for electrochemical energy storage, catalysis, and gas sensing applications.
authors.affiliation: State Key Laboratory of Silicon Materials and Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, People's Republic of China.
authors.forename: Xinhui
authors.initials: X
authors.lastname: Xia
authors.forename: Jiangping
authors.initials: J
authors.lastname: Tu
authors.forename: Yongqi
authors.initials: Y
authors.lastname: Zhang
authors.forename: Xiuli
authors.initials: X
authors.lastname: Wang
authors.forename: Changdong
authors.initials: C
authors.lastname: Gu
authors.forename: Xin-Bing
authors.initials: XB
authors.lastname: Zhao
authors.forename: Hong Jin
authors.initials: HJ
authors.lastname: Fan
mesh_terms: D025802:Electric Capacitance; D004553:Electric Conductivity; D011211:Electric Power Supplies; D004581:Electronics / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008422:Materials Testing; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure*; D010087:Oxides / Q000737:chemistry
chemical_list: D010087:Oxides