Porous carbon cubes decorated with cobalt nanoparticles for oxygen evolution catalysis in Zn‐air batteries

For commercialization of zinc-air batteries, it is important to replace expensive noble metal catalysts with inexpensive carbonaceous materials. Herein, an efficient oxygen evolution reaction (OER) catalyst composed of a unique porous tunnel carbon cube and cobalt nanoparticles ([email protected]) was fabricated to facilitate oxygen diffusion and create electron conduction networks. As an OER catalyst for zinc-air batteries (ZABs), the resulting [email protected] demonstrate enhanced OER activity, similar to that of the benchmark RuO2. In OER performance, [email protected] exhibits the excellent mass activity of 49.9 mA mg−1 at overpotential (η) of 0.47 V and the high current density of 91.5 mA cm−2 at 1.75 V (vs RHE), compared to commercial RuO2 catalysts. The use of [email protected] as the OER catalyst for ZAB maintains stable charge overpotential with as little as 0.05 V variation during 250 cycles, which extends the stable discharge-charge cycle performance compared to RuO2. This work highlights a facile approach to fabricate OER catalysts without noble metals for enabling stable charge state and long life ZABs.