title: Homologous NiO//Ni2P nanoarrays grown on nickel foams: a well matched electrode pair with high stability in overall water splitting.
abstract: Homologous NiO, Ni3S2, and Ni2P nanoarrays were obtained by thermolysis, sulfuration, and phosphorization of the Ni(SO4)0.3OH1.4belt-like precursors. The three types of porous nickel compound films grown on nickel foam with a thickness of ∼8 μm have been used as anodes and cathodes in a two-electrode setup for overall water splitting. The electrode pairing of NixMy//NixMy(M = O, S, and P) for electrocatalysis in order of superiority is as follows: NiO//Ni2P > Ni3S2//Ni2P > Ni2P//Ni2P > Ni3S2//Ni3S2> NiO//Ni3S2> NiO//NiO. The other two sets of NixMywith different thicknesses of ∼5 and ∼11 μm also follow the abovementioned order. The well matched electrode pair of NiOOER//Ni2PHERonly needs 1.65 V, whereas NiO//NiO pair needs 1.84 V to afford the current of 10 mA cm-2in 1 mol L-1of aqueous KOH solution. In particular, the current density retention of the NiO//Ni2P reached 92% after 120 hours of electrolysis at 1.70 V (NiO//NiO only maintains 72% after 30-hour electrolysis). The novelty of this study focuses on fabricating a well matched electrode pair to substantially enhance its electrochemical performance and durability, which would provide a new insight into developing non-noble, highly efficient, and stable electrode pairs.
authors.affiliation: School of Chemistry and Environment, Beihang University, Beijing 100191, China. zhouwei@buaa.edu.cn guolin@buaa.edu.cn.
authors.forename: Jinlong
authors.identifier: http://orcid.org/0000-0002-0870-2248
authors.initials: J
authors.lastname: Zheng
authors.affiliation: School of Chemistry and Environment, Beihang University, Beijing 100191, China. zhouwei@buaa.edu.cn guolin@buaa.edu.cn.
authors.forename: Wei
authors.identifier: http://orcid.org/0000-0003-0659-7824
authors.initials: W
authors.lastname: Zhou
authors.affiliation: School of Chemistry and Environment, Beihang University, Beijing 100191, China. zhouwei@buaa.edu.cn guolin@buaa.edu.cn.
authors.forename: Tong
authors.initials: T
authors.lastname: Liu
authors.affiliation: School of Chemistry and Environment, Beihang University, Beijing 100191, China. zhouwei@buaa.edu.cn guolin@buaa.edu.cn.
authors.forename: Shijie
authors.initials: S
authors.lastname: Liu
authors.affiliation: School of Chemistry and Environment, Beihang University, Beijing 100191, China. zhouwei@buaa.edu.cn guolin@buaa.edu.cn.
authors.forename: Chengbo
authors.initials: C
authors.lastname: Wang
authors.affiliation: School of Chemistry and Environment, Beihang University, Beijing 100191, China. zhouwei@buaa.edu.cn guolin@buaa.edu.cn.
authors.forename: Lin
authors.initials: L
authors.lastname: Guo