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Reducing Oxygen Evolution Reaction Overpotential in Cobalt‐Based Electrocatalysts via Optimizing the “Microparticles‐in‐Spider Web” Electrode Configurations
Author(s) -
Guo Qi,
Mao Jiajun,
Huang Jianying,
Wang Zixi,
Zhang Yanyan,
Hu Jun,
Dong Jianing,
Sathasivam Sanjayan,
Zhao Yan,
Xing Guichuan,
Pan Hui,
Lai Yuekun,
Tang Yuxin
Publication year - 2020
Publication title -
small
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.785
H-Index - 236
eISSN - 1613-6829
pISSN - 1613-6810
DOI - 10.1002/smll.201907029
Subject(s) - overpotential , oxygen evolution , materials science , cobalt , chemical engineering , electrode , electron transfer , electrochemistry , catalysis , inorganic chemistry , chemistry , photochemistry , organic chemistry , engineering
Sluggish kinetics of the multielectron transfer process is still a bottleneck for efficient oxygen evolution reaction (OER) activity, and the reduction of reaction overpotential is crucial to boost reaction kinetics. Herein, a correlation between the OER overpotential and the cobalt‐based electrode composition in a “Microparticles‐in‐Spider Web” (MSW) superstructure electrode is revealed. The overpotential is dramatically decreased first and then slightly increased with the continuous increase ratio of Co/Co 3 O 4 in the cobalt‐based composite electrode, corresponding to the dynamic change of electrochemically active surface area and charge‐transfer resistance with the electrode composition. As a proof‐of‐concept, the optimized electrode displays a low overpotential of 260 mV at 10.0 mA cm −2 in alkaline conditions with a long‐time stability. This electrochemical performance is comparable and even superior to the most currently reported Co‐based OER electrocatalysts. The remarkable electrocatalytic activity is attributed to the optimization of the electrochemically active sites and electron transfer in the MSW superstructure. Theoretical calculations identify that the metallic Co and Co 3 O 4 surface catalytic sites play a vital role in improving electron transport and reaction Gibbs free energies for reducing overpotential, respectively. A general way of boosting OER kinetics via optimizing the electrode configurations to mitigate reaction overpotential is offered in this study.