Co/nitrogen-doped carbon nanocomposite derived from self-assembled metallogels as efficient bifunctional oxygen electrocatalyst for Zn-air batteries

Rational design and exploration of highly efficient nonprecious metal-based bifunctional electrocatalysts are vital for metal-air batteries. Herein, a folic acid based metal-organic gels (MOG) is synthesized based on co-ordination induced self-assemble strategy, which affords well-defined dispersion cobalt implanted into N-doped porous carbon (CoNC-MOG-x) via pyrolysis. The as-obtained CoNC-MOG-x possesses well distributed Co-nanoparticles and larger accessible surface areas than the CoNC without self-assemble process. Taking advantage of the unique structure, the CoNC-MOG-9 exhibits good oxygen reduction reaction activity, and the half-wave potentials for oxygen reduction reaction is 0.815 V. In addition, it also displays high oxygen evolution reaction activity with overpotential of 0.40 V at 10 mA cm(-2) and a Tafel slope of 76 mV dec(-1). Furthermore, integrated CoNC-MOG-9 cathode in an all-solid-state zinc-air battery exhibits a high specific power of 63 mW cm(-2) as well as excellent stability and durability.

Automated summary

The folic acid based metal-organic gels synthesized through coordination induced self-assemble strategy show good dispersion and larger accessible surface areas, providing potential to enhance the oxygen reduction reaction and oxygen evolution reaction activities in nonprecious metal based bifunctional electrocatalysts for metal-air batteries.