ScholarWorks@경상국립대학교

초록

Developing robust and highly bifunctional electrocatalysts for the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) is key for achieving effective rechargeable Zn-air battery. Herein, a zeolitic imidazole framework is synthesized via pulsed laser ablation in liquid, pyrolyzed into N-doped carbon (NC), and utilized as a self-template for decorating NiCoFePdIr (HEA) nanoparticles (NC-HEA) using a wet chemical approach. The optimized NC-HEA catalyst demonstrates an impressive ORR halfwave potential of 0.86 V vs. a reversible hydrogen electrode (RHE), outperforming Pt/C, and an OER overpotential of 400 mV at 10 mA cm-2, comparable to IrO2. This outstanding activity can be ascribed to the presence of N-rich carbon, enhanced surface area, excellent electronic conductivity, and porous structure, which collectively facilitate effective mass transfer during the ORR and OER. Density functional theory computations demonstrate that the strong interaction within the NC matrix and HEA in the NC-HEA catalyst improves the catalytic activity for both reactions. Furthermore, a rechargeable Zn-air battery incorporating the NC-HEA demonstrates excellent activity, achieving an energy density of 140 mW cm-2 and amazing cycle stability. The proposed method offers a simple and rapid approach for creating progressive oxygen bifunctional electrocatalysts with potential applications across various energy technologies.

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