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Oxygen Evolution Activity of Co–Ni Nanochain Alloys: Promotion by Electron Injection
Author(s) -
Yuan Xiaotao,
Riaz Muhammad Sohail,
Wang Xin,
Dong Chenlong,
Zhang Zhe,
Huang Fuqiang
Publication year - 2018
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201800044
Subject(s) - overpotential , electrocatalyst , materials science , alloy , oxide , oxygen evolution , chemical engineering , nanoparticle , metal , oxygen , electrode , nanotechnology , metallurgy , electrochemistry , chemistry , organic chemistry , engineering
Metal alloy nanoparticles have shown promising applications in electrocatalysis. However, the nanoparticles usually suffer from limited charge‐transfer efficiency, which can be solved by preparing one‐dimensional materials. Herein, Co–Ni alloy nanochains are prepared by a direct‐current arc‐discharge method. The nanochains, comprised of mutually coupled uniform nanospheres, can range up to several micrometers in size. When the alloy is exposed to air or under the electro‐oxidation process, a metal–metal‐oxide heterostructure is obtained. The alloy can inject electrons into the oxide, which makes it more suitable for electrocatalysis. The composition of the samples can be changed by varying the ratio of Ni/Co (i.e., Co, Co 7 Ni 3 , Co 5 Ni 5 , Co 3 Ni 7 , Ni) in the synthesis process. The nanochains show good oxygen evolution performance that correlates with the Ni/Co ratio. Co 7 Ni 3 demonstrates optimal activity with an onset point of 1.50 V vs. reversible hydrogen electrode (RHE) and overpotential of 350 mV at 10 mA cm −2 . The alloy nanochains also show excellent durability with 95.0 % current retention after a long‐term test for 12 h.