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

Abstract

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 onset = 1.06 V) and half-wave potential ( E 1/2 = 0.85 V), coupled with the small overpotential ( η ) 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 ( η = 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. • CoFe-NCNFs were fabricated by a facile pyrolysis method. • The unique structure offers enlarged specific active area and improved stability. • Multi-component synergetic effect brings out trifunctional catalytic activities. • The catalyst performs well in Zn–air battery and water electrolysis.