Aminouracil-assisted synthesis of CoFe decorated bougainvillea-like N-doped carbon nanoflowers for boosting Zn-air battery and water electrolysis

Highly efficient, low-cost, and long-term stable catalysts are of great significance as promising alternatives to noble metal-based catalysts for oxygen reduction reaction (ORR), oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in energy-related devices. Herein, CoFe decorated bougainvillea-like N-doped carbon nanoflowers (CoFe-NCNFs) are synthesized through a one-step aminouracil-assisted pyrolysis strategy. Benefit from the abundant active sites from the flower-like structures, along with synergistic effect between multi compositions, the catalyst displays distinct improvement on the ORR with the more positive onset potential (E(ons)et = 1.06 V) and half-wave potential (E-1/2 = 0.85 V), coupled with the small overpotential (eta) of 323 mV and 212 mV at 10 mA cm(-2) for OER and HER, respectively. In view of the trifunctional properties, a rechargeable Zn-air battery is constructed by self-assembly, possessing large power density (116.1 mW cm(-2)), small voltage gap (0.865 V at 5 mA cm(-2)), and superior durability for 110 h. Also, the catalyst demonstrated excellent catalytic activity and stability in water electrolysis (eta = 1.65 V at 10 mA cm(-2) for 20 h). This research offers a breakthrough in developing advanced multifunctional non-precious metal-based electrocatalysts in metal-air batteries, water electrolysis, and other energy-correlated devices.

Automated summary

In this study, highly efficient and cost-effective non-precious metal-based electrocatalysts were synthesized for oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and hydrogen evolution reaction (HER). The catalyst exhibited improved performance with positive onset potential, small overpotential, and excellent stability. It shows great potential for applications in metal-air batteries and water electrolysis.