Facile Microwave Synthesis of Kilogram‐Scale Electrocatalysts with Nanocarbons Bridged Cobalt Active Sites for Enhanced Oxygen Electrocatalysis

Abstract Oxygen reductions and evolution reactions (ORR/OER) are pivotal electrochemical processes in fuel cells and metal‐air batteries, yet the rapid, large‐scale production of efficient ORR/OER electrocatalysts remains challenging. Herein, a groundbreaking microwave‐synthesis strategy is presented that enables the rapid and facile preparation of kilogram‐scale ORR/OER electrocatalysts. The unique microwave irradiation generates instantaneous thermal energy, facilitating the formation of nano‐carbon bridges that interconnect high‐density active sites comprising cobalt single atoms and nanoparticles. This innovative architectural configuration significantly enhances the kinetics of electron/mass transfer and maximizing the accessibility of active sites. The optimized carbon‐bridged cobalt catalyst (CBCo‐800) demonstrates a commendable half‐wave potential (E _1/2) of 0.86 V versus RHE and a minimal overpotential difference (ΔE) of 0.696 V. Furthermore, lab‐assembled zinc‐air battery utilizing CBCo‐800 achieved a great specific capacity of 794 mAh g⁻¹ and sustained over 650 h, outperforming commercial Pt/C and RuO₂ catalysts. Density functional theory (DFT) calculations elucidate that the nanocarbon bridge between the dual‐active sites boosts oxygen activation and optimizes the adsorption/desorption dynamics of *OH/*OOH intermediates, thereby lowering the energy barriers for ORR/OER. This study offers a facile solution for producing dual‐active site materials, and also establishes a robust platform for the mass production of high‐performance electrocatalysts.