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Defect‐Driven Enhancement of Electrochemical Oxygen Evolution on Fe–Co–Al Ternary Hydroxides
Author(s) -
Sun Yixuan,
Xia Yuanyuan,
Kuai Long,
Sun Hongxia,
Cao Wei,
Huttula Marko,
Honkanen AriPekka,
Viljanen Mira,
Huotari Simo,
Geng Baoyou
Publication year - 2019
Publication title -
chemsuschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.412
H-Index - 157
eISSN - 1864-564X
pISSN - 1864-5631
DOI - 10.1002/cssc.201900831
Subject(s) - overpotential , oxygen evolution , catalysis , electrochemistry , cobalt , ternary operation , transition metal , materials science , hydroxide , density functional theory , chemical engineering , electrochemical energy conversion , inorganic chemistry , valence (chemistry) , oxygen , water splitting , chemistry , electrode , computational chemistry , photocatalysis , programming language , biochemistry , organic chemistry , computer science , engineering
Efficient, abundant and low‐cost catalysts for the oxygen evolution reaction (OER) are required for energy conversion and storage. In this study, a doping–etching route has been developed to access defect rich Fe–Co–Al (Fe–Co–Al‐AE) ternary hydroxide nanosheets for superior electrochemical oxygen evolution. After partial etching of Al, ultrathin Fe 3 Co 2 Al 2 ‐AE electrocatalysts with a rich pore structure are obtained with a shift of the cobalt valence state towards higher valence (Co 2+ →Co 3+ ), along with a substantial improvement in the catalytic performance. Fe 3 Co 2 Al 2 ‐AE shows a notably lower overpotential of only 284 mV at a current density of 10 mA cm −2 and double the OER mass activity of the etching‐free Fe 3 Co 2 Al 2 with an overpotential of 350 mV. Density functional theory shows the leaching of Al changes the rate‐determining step of the OER from conversion of *OOH into O 2 on Fe 3 Co 2 Al 2 to formation of OOH from *O on the Al‐defective catalysts. This work demonstrates an effective route to design and synthesize transition metal electrocatalysts and provides a promising alternative for the further development of oxygen evolution catalysts.