Well-Dispersed Entropy-Driven Alloy Particles on Carbon Black From Stepwise Alloying Strategy and Their Bifunctional Electrocatalytic Performance for Zinc-Air Batteries

초록

The rational design of highly active and durable bifunctional electrocatalysts is essential for advancing next-generation energy conversion and storage technologies. Herein, we report a stepwise alloying strategy for synthesizing ultrasmall, well-dispersed entropy-driven nanoparticles with a Pt-centered structure incorporating Fe, Co, Ni, and Cu supported on cost-effective carbon black (SA-CB). Electrochemical studies demonstrate that SA-CB exhibits outstanding bifunctional performance, with an onset potential of 1.01 V and a half-wave potential of 0.84 V for the oxygen reduction reaction, together with a low oxygen evolution reaction overpotential of 0.36 V at 10 mA cm-2. Importantly, when integrated into rechargeable zinc-air batteries (ZABs), SA-CB delivers an open-circuit voltage of 1.48 V, a peak power density of 114.6 mW cm-2, and a specific capacity of 725.0 mAh gZn -1, surpassing state-of-the-art benchmarks. Density functional theory calculation provides a new mechanistic paradigm including multi-metal-induced d-band modulation and optimal d-/p-band alignment, which uniquely enables balanced adsorption of electrocatalytic intermediates. These results establish stepwise alloying as an effective strategy for tailoring the structural and electronic properties of entropy-driven nanoparticle catalysts and highlight their practical promise for high-performance, sustainable ZABs.

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