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Nanometric Ni 5 P 4 Clusters Nested on NiCo 2 O 4 for Efficient Hydrogen Production via Alkaline Water Electrolysis
Author(s) -
Zhang Tao,
Yang Kena,
Wang Cheng,
Li Shanyu,
Zhang Qiqi,
Chang Xuejiao,
Li Juntao,
Li Simo,
Jia Shuangfeng,
Wang Jianbo,
Fu Lei
Publication year - 2018
Publication title -
advanced energy materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.08
H-Index - 220
eISSN - 1614-6840
pISSN - 1614-6832
DOI - 10.1002/aenm.201801690
Subject(s) - tafel equation , overpotential , hydrogen production , electrocatalyst , water splitting , electrolysis of water , materials science , electrolysis , alkaline water electrolysis , platinum , catalysis , hydrogen , inorganic chemistry , dissociation (chemistry) , chemical engineering , electrode , chemistry , electrochemistry , electrolyte , photocatalysis , organic chemistry , biochemistry , engineering
A number of non‐noble catalysts are developed for hydrogen production via acidic water electrolysis. Nevertheless, for the more economical alkaline hydrogen generation, the restricted kinetics of the water dissociation Volmer step along with its following proton recombination Tafel step for these non‐noble electrocatalysts generally lead to sluggish hydrogen‐production process. Here, a facile method is designed to nest nanometric Ni 5 P 4 clusters on NiCo 2 O 4 (achieving Ni 5 P 4 @NiCo 2 O 4 ) by a phosphating process of NiO clusters on NiCo 2 O 4 . Acting as a high‐efficiency electrode for alkaline water electrolysis, the Ni 5 P 4 @NiCo 2 O 4 can efficiently and preferentially convert H 2 O to H 2 with a low overpotential of 27 mV at 10 mA cm −2 and the Tafel slope of 27 mV dec −1 , which are comparable to the results for platinum and superior than those of the state‐of‐the‐art platinum‐free electrocatalysts. Density functional theory calculations confirm that NiCo 2 O 4 species exhibit a higher ability to electrolyze water into H* intermediate and then Ni 5 P 4 clusters facilitate the subsequent desorption of the H 2 products. Profiting from the promoted kinetic steps, the Ni 5 P 4 @NiCo 2 O 4 electrocatalyst is promising for scalable alkaline hydrogen production.