FeCo nanoalloys encapsulated in N-doped carbon nanofibers as a trifunctional catalyst for rechargeable Zn-air batteries and overall water electrolysis

Abstract

Developing low-cost, high-efficiency and durable trifunctional electrocatalysts for enhancing the speed of oxygen reduction, oxygen evolution and hydrogen evolution reactions (ORR, OER and HER) is critical for expanding the industrial production and the commercial application of rechargeable Zn-air batteries and water electrolysis, but it still exists as a tremendous challenge. Herein, FeCo nanoalloys embedded into N-doped carbon nanofibers was prepared as a superior trifunctional catalyst for ORR, OER and HER by a universal and facile method. Under the synergistic effect of FeCo nanoalloys and N-doped carbon nanofibers, the Fe, Co/N-C catalyst exhibits half-wave potential of 0.86 V for ORR, and overpotentials of 388 mV and 249 mV at 10 mA·cm−2 for OER and HER, respectively. What’s more, the Zn-air battery based on Fe, Co/N-C catalyst displayed a considerable open-circuit voltage of 1.5 V and a continuous cycle life span of 210 h. Moreover, this catalyst was also used as the sole catalyst in overall water splitting to show excellent performance. This work provides an effective way to design efficient and durable multifunctional electrocatalysts, which will facilitate the development of high-performance multifunctional catalysts and their application in renewable energy applications.