title: Single-Crystalline Ultrathin Nickel Nanosheets Array from In Situ Topotactic Reduction for Active and Stable Electrocatalysis.
abstract: Simultaneously synthesizing and structuring atomically thick or ultrathin 2D non-precious metal nanocrystal may offer a new class of materials to replace the state-of-art noble-metal electrocatalysts; however, the synthetic strategy is the bottleneck which should be urgently solved. Here we report the synthesis of an ultrathin nickel nanosheet array (Ni-NSA) through in situ topotactic reduction from Ni(OH)2 array precursors. The Ni nanosheets showed a single-crystalline lamellar structure with only ten atomic layers in thickness and an exposed (111) facet. Combined with a superaerophobic (low bubble adhesive) arrayed structure the Ni-NSAs exhibited a dramatic enhancement on both activity and stability towards the hydrazine-oxidation reaction (HzOR) relative to platinum. Furthermore, the partial oxidization of Ni-NSAs in ambient atmosphere resulted in effective water-splitting electrocatalysts for the hydrogen-evolution reaction (HER).
authors.affiliation: State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029 (P.R. China).
authors.forename: Yun
authors.initials: Y
authors.lastname: Kuang
authors.affiliation: State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029 (P.R. China).
authors.forename: Guang
authors.initials: G
authors.lastname: Feng
authors.affiliation: State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029 (P.R. China).
authors.forename: Pengsong
authors.initials: P
authors.lastname: Li
authors.affiliation: State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029 (P.R. China).
authors.forename: Yongmin
authors.initials: Y
authors.lastname: Bi
authors.affiliation: State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029 (P.R. China).
authors.forename: Yaping
authors.initials: Y
authors.lastname: Li
authors.affiliation: State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029 (P.R. China). sunxm@mail.buct.edu.cn.
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Sun
keywords: electrocatalysis; nanosheets; nickel; single crystals; ultrathin films