Electrospun Fe/Zn co-doped porous carbon nanofibers: Dual-functional catalysts for high-efficiency oxygen reduction and ultra-stable supercapacitors

The development of sustainable energy technologies depends critically on the search for effective, reasonably priced catalysts for the oxygen reduction reaction (ORR) and high-capacitance supercapacitors. This study introduces a novel iron and zinc co-doped porous carbon nanofiber catalyst (Fe/Zn-N-C-900), fabricated through an innovative electrospinning technique, which is mainly improved by adding β-cyclodextrin (β-CD) and zinc chloride (ZnCl 2 ) to the spinning solution. The β-CD can reduce the nanofiber diameter, together with zinc chloride, creates a rich hierarchical pore structure. With an onset potential of 0.97 V in alkaline and 0.79 V in acidic media, the resultant Fe/Zn-N-C-900 catalyst exhibits remarkable ORR activity and an impressive specific surface area of 1075.39 m 2 ·g -1 . With an energy density of 38.34 Wh·kg -1 , it maintains 98 % of its capacitance after 5000 charge-discharge cycles and reaches a specific capacitance of 332 F·g -1 at 1 A·g -1 in supercapacitor tests. The exceptional performance is attributed to the high surface area, hierarchical porous structure, and synergistic effects of iron and zinc co-doping, according to combined characterization and density functional theory calculations.