The development of efficient bifunctional electrocatalysts for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is crucial for advancing rechargeable zinc–air batteries (ZABs). However, these reactions remain significantly constrained by sluggish kinetics due to their four-electron transfer processes. Herein, cobalt nanoparticles (Co(Zn)-NPs-P) were uniformly anchored on nitrogen-doped carbon via site-specific growth, achieved through the pyrolysis of a polyaniline (PANI)-modified CoZn zeolitic imidazolate framework (ZIF) precursor. ZIFs exhibit uniform porosity and unique coordination environment, which can yield and well-dispersed nanoparticles upon pyrolysis. PANI serves as a rich source of nitrogen and carbon, and prevents Co nanoparticles agglomeration, thereby enhancing the ORR/OER catalytic activity. Co(Zn)-NPs-P demonstrates remarkable catalytic performance in alkaline electrolyte, achieving an exceptional ORR half-wave potential ( E 1/2 = 0.88 V RHE (vs. reversible hydrogen electrode)) and high onset potential ( E onset = 0.96 V RHE ), as well as an excellent OER performance (overpotential of 340 mV at 10 mA cm −2 ) and a Tafel slope (117.79 mV dec −1 ). The Co(Zn)-NPs-P-based ZAB delivers a high specific capacity of 788.3 mAh g Zn −1 , extended cycling stability (180 h), and power density (106 mW cm −2 ). Consequently, this PANI-assisted pyrolyzed Co nanoparticle electrocatalyst design provides a versatile approach for constructing multifunctional electrocatalysts tailored for metal–air batteries.
Xu et al. (Fri,) studied this question.