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Electrochemical Water Splitting by Pseudo‐spinel, Disordered and Layered Lithium Nickel Oxides: Correlation between Structural Motifs and Catalytic Properties
Author(s) -
Wu Jian,
Wang Guofu,
Du Juan,
Liu J. Ping,
Wang Jianguo,
Fan Weibin
Publication year - 2018
Publication title -
chemcatchem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.497
H-Index - 106
eISSN - 1867-3899
pISSN - 1867-3880
DOI - 10.1002/cctc.201800200
Subject(s) - tafel equation , spinel , catalysis , electrocatalyst , nickel , lithium (medication) , materials science , oxide , electrochemistry , chemistry , inorganic chemistry , chemical engineering , metallurgy , electrode , medicine , endocrinology , engineering , biochemistry
In this work, three different structures of lithium nickel oxide (LNO) synthesized by simple methods as inexpensive and efficient electrocatalyst for OER were presented. The catalytic activities of LNO catalysts for OER were pseudo‐spinel (PS‐LiNiO 2 ) > disordered (DO‐LiNiO 2 ) > layered ( L ‐LiNiO 2 ) lithium nickel oxide. Particularly, PS‐LiNiO 2 demonstrated much lower tafel slope of 62 mV dec −1 with the highest durability whereas the layered LNO catalysts exhibited the higher tafel slope of 88 mV dec −1 , respectively. To elucidate the origin of high activities of LNO catalysts, three structures of LNO were studied by EXAFS measurements and DFT theoretical calculation. Compared to L ‐LiNiO 2 , PS‐LiNiO 2 , including Ni 4 O 4 cubane structural motifs, exhibited higher valent states and lower Ni d‐band center to drive the catalytic reaction. Thus, our results demonstrated that the activities of LNO can be optimized by controlling the value states, chemical and local electronic structure of Ni via novel design approaches.