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Download fileDeciphering the Dynamic Structure Evolution of Fe- and Ni-Codoped CoS2 for Enhanced Water Oxidation
journal contribution
posted on 2022-03-10, 18:35 authored by Wenfeng Peng, Amol Deshmukh, Ning Chen, Zhengxing Lv, Shijing Zhao, Jiong Li, Bingmin Yan, Xiang Gao, Lu Shang, Yutong Gong, Lailei Wu, Mingyang Chen, Tierui Zhang, Huiyang GouMultimetal
doping is a promising strategy to achieve high-performance
electrocatalysts for the oxygen evolution reaction (OER) due to synergistic
effects; however, understanding the dynamic structure evolution and
clarifying the catalytic mechanism of each individual doping metal
in multimetal-based electrocatalysts remain elusive. Here, we report
the synthesis of homogeneous single-metal and bimetal doping sulfides
with a pyrite structure for OER catalysts via a high-pressure and
high-temperature (HPHT) technique; operando Raman and X-ray absorption
spectroscopy (XAS) studies are performed to capture the dynamic evolution
during the OER process. Our results find that an Fe- and Ni-codoped
CoS2 electrocatalyst exhibits significantly improved OER
activity with an overpotential of 242 (295) mV at 10 (100) mA cm–2 and robust stability over 500 h in an alkaline medium.
Operando analysis reveals that Fe and Ni incorporations not only expedite
the dynamic response of self-reconstructions of the Fe,Ni-CoS2 surface but also accelerate the oxidation of Co and Fe into
high-valence oxyhydroxides while suppressing nickel oxidation to form
Ni(OH)2 for optimized activity and robust stability. This
finding provides a fundamental understanding of the composition design,
dynamic reaction pathways, and controlling principle for highly active
multimetal-based OER catalysts.
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Keywords
ray absorption spectroscopybimetal doping sulfidesoxygen evolution reactionoperando analysis revealsdynamic reaction pathwaysoer catalysts viabased oer catalystssuppressing nickel oxidationindividual doping metalhighly active multimetal2 </ subdynamic structure evolutiondynamic evolutionpyrite structureoperando ramandynamic responseoer processvalence oxyhydroxidessynergistic effectsrobust stabilityresults findpromising strategyperformance electrocatalystsoptimized activityhomogeneous singlefinding providescontrolling principlecomposition designcatalytic mechanismalso acceleratealkaline medium500 h