N- & S-co-doped carbon nanofiber network embedded with ultrafine NiCo nanoalloy for efficient oxygen electrocatalysis and Zn-air batteries.

A novel 3D N- & S-co-doped carbon nanofiber network embedded with ultrafine NiCo oxide nanoparticles is explored by a facile surfactant-assisted electrospinning method. This catalyst has several structural advantages including ultrafine active sites (2-8 nm), hierarchical pores, and abundant defects, allowing for much higher OER/ORR activity compared to commercial IrO2 and Pt/C catalysts. The potential gap (ΔE) of OER and ORR metrics for NSCFs/Ni-Co-NiCo2O is 0.69 V and the Zn-air battery equipped with NSCFs/Ni-Co-NiCo2O as the air cathode delivers a maximum power density of 171.24 mW cm-2 at 268 mA cm-2. Furthermore, the unique structure of the 3D carbon nanofiber network embedded with ultrafine nanoparticles results in superior stability with negligible degradation in activity after 380 h of continuous operation.