Hydrated Tripodal Polydentate Terpyridine Cobalt Complex-Based Metal–Organic Gel as a Bifunctional OER/ORR Electrocatalyst

In the pursuit of a technological breakthrough in zinc-air batteries, it is critical to find economical, durable, and high-performance catalysts for the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) to accelerate the slow reaction kinetics. Herein, a one-pot method was employed to synthesize the polymer within a mixed solvent of CHCl3 and CH3OH (v/v = 2:1). The resulting polymer can be well-dispersed in deionized water to form an aqueous metal–organic gel (MOG). Testing has revealed that Co-MOG exhibits dual catalytic properties for both the OER and ORR, a characteristic that is notably rare in original MOG materials. Furthermore, it demonstrates exceptional long-term charge–discharge cycling stability in zinc-air batteries, outperforming several reported Co-based catalysts for the OER and ORR. X-ray absorption spectroscopy and density-functional theory (DFT) calculations indicate that the CoN3 configuration serves as the catalytically active site of the material. In conclusion, this work supports the application of MOGs as unique bifunctional electrocatalysts for the OER and ORR in metal-air batteries.