Research Article Issue
Synergy between isolated Fe and Co sites accelerates oxygen evolution
Nano Research 2023, 16 (2): 2218-2223
Published: 22 October 2022

Dual-metal catalysts with synergistic effect exhibit enormous potential for sustainable electrocatalytic applications and mechanism research. Compared with mono-metal-site catalysts, dual-metal-site catalysts exhibit higher efficiency for the oxygen evolution reaction (OER) due to reduced energy barrier of the process involving proton-coupled multi-electron transfer. Herein, we construct dual-metal Fe-Co sites coordinated with nitrogen in graphene (FeCo-NG), which exhibits high OER performance with onset overpotential of only 126 mV and Tafel slope of 120 mV·dec−1, showing that the rate-determining step is controlled by the single-electron transfer step. Theoretical calculations reveal that the FeN4 site exhibits lower OER overpotential than the CoN4 site due to appropriate adsorption energy of OOH* on the former, while the O* adsorbed on the adjacent Co site could stabilize the OOH* on the FeN4 site through hydrogen bond interaction.

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