Efficient Catalysis for Zinc-Air Batteries by Multiwalled Carbon Nanotubes-Crosslinked Carbon Dodecahedra Embedded with Co-Fe Nanoparticles

The design and fabrication of nanocatalysts with high accessibility and sintering resistance remain significant challenges in heterogeneous electrocatalysis. Herein, a novel catalyst is introduced that combines electronic pumping with alloy crystal facet engineering. At the nanoscale, the electronic pump leverages the chemical potential difference to drive electron migration from one region to another, separating and transferring electron-hole pairs. This mechanism accelerates the reaction kinetics and improves the reaction rate. The interface electronic structure optimization enables the CoFe/carbon nanotube (CNT) catalyst to exhibit outstanding oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) performance. Specifically, this catalyst achieves an ORR half-wave potential (E₁/₂) of 0.895 V, outperforming standard Pt/C and RuO₂ electrocatalysts in terms of both specific activity and stability. It also demonstrates excellent electrochemical performance for OER, with an overpotential of only 287 mV at a current density of 10 mA cm⁻². Theoretical calculations reveal that the carefully designed crystal facets reduce the energy barrier of the rate-determining steps for both ORR and OER, optimizing O₂ adsorption and promoting the oxygen capture process. This study highlights the potential of developing cost-effective bifunctional ORR-OER electrocatalysts, offering a promising strategy for advancing Zn-air battery technology.