Engineering of active site coupling to facilitate interatomic charge transfer for bifunctional oxygen electrocatalysis

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Interatomic charge transfer emerges as a robust technique for enhancing catalytic efficacy in key energy reactions, specifically the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Despite its potential, advancing simultaneous improvements in reversible oxygen catalysis pose considerable challenges. Herein, we detailed an active site coupling engineering method to create a CoCu@NSC bifunctional oxygen electrode. In this configuration, OER-active Cu sites were alloyed with ORR-active Co within a N/S-doping carbon nanobox. This arrangement yielded a half-wave potential of 0.924 V for ORR, alongside an overpotential of η10 = 356 mV for OER. The fabricated CoCu@NSC cathode yielded a discharge capacity of 768 mAh/gZn, a peak power density of 295 mW/cm2, and extensive cycling durability. Work function assessments indicated that the chemical integration of Co and Cu components at the atomic level promoted interfacial charge redistribution, effectively optimizing the adsorption-desorption dynamics of intermediates at the active sites, thereby substantially enhancing the catalytic performance for both OER and ORR. Additionally, doping with N/S species enhanced the conductivity of the hollow carbon matrix, facilitating more effective mass and charge transport pathways. These insights illuminate a compelling approach for the design and synthesis of effective bifunctional oxygen electrodes that is pivotal for advanced energy storage advice.