Controllable Microwave Heating for Energy‐Efficient and Universal Synthesis of Atomically Dispersed Metals on Nitrogen‐Doped Carbon Nanofibers

Abstract

Abstract Carbon‐supported single‐atom catalysts (SACs) have shown great potential in electrocatalysis, whereas traditional synthesis methods typically involve energy‐intensive carbonization processes and unfavorable atomic migration and aggregation. Herein, an energy‐efficient and universal strategy is developed to rapidly fabricate various SACs on nitrogen‐doped hierarchically porous carbon nanofibers (M‐TM/NPCNFs, TM = Fe, Co, Ni, FeCo, and FeNi) by electrospinning and controllable microwave heating technique. Such microwave heating technique enables an ultrafast heating rate (ramping to 900 °C in 5 min) to greatly suppress the random migration and aggregation of metal species. Meanwhile, the energy consumption and time can be reduced to 2.5% and less than half an hour, respectively, compared to traditional pyrolysis methods. As a proof of concept, the synthesized M‐Fe/NPCNFs with abundant Fe‐N 4 sites exhibit remarkable oxygen reduction reaction (ORR) activity with a high half‐wave potential ( E 1/2 = 0.88 V) in alkaline media, excellent performance in Zn‐air battery with a large discharge specific capacity (801 mAh g −1 ) and long‐term cycle durability (over 1000 h), demonstrating the great potential of the microwave heating technique in efficient fabrication of SACs for energy related applications.