Durable oxygen evolution reaction of one dimensional spinel CoFeO nanofibers fabricated by electrospinning.

One dimensional spinel CoFeO nanofibers were synthesized the electrospinning technique. The nanofibers were calcined at different temperatures. All CoFeO nanofibers show excellent oxygen evolution reaction (OER) performance. The nanofibers calcined at 750 °C have a multi-particle nanochain structure. The nanochain exhibits excellent catalytic performance for OER in 1 M KOH (pH = 14) producing a current density of 10 mA cm at an overpotential of 0.34 V, and the small onset potential of 1.32 V RHE, better than that of the commercial Ir/C (20%) catalyst. Furthermore, the stability of CoFeO multi-particle nanochains toward the OER decreases by only 0.78% even after a long period of 80 000 s. Our finding suggests that CoFeO nanofibers with a multi-particle nanochain structure could serve as a new group of OER electrocatalysts with excellent performance.