▎ 摘　　要

By combining the techniques of electrospinning and heat-treatment, N-doped graphene (NG) were in situ grown on cobalt-containing electronspun carbon nanofibers (CNF) to form three-dimensional (3D) interconnected fiber network structure. The effect of cobalt (Co) content on the oxygen reduction reaction (ORR) activity of the as-prepared samples was studied. It is demonstrated that both the formation of NG and introduction of Co significantly increase the electrocatalytic activity. The hybrid shows optimized ORR performance when the weight ratio of Co(NO3)(2)center dot 6H(2)O to PAN in electronspun solution is 1:10. The as-obtained catalyst exhibits superior ORR catalytic performance with onset potential of 0.84 V (vs RHE), near four electron transfer pathway. In addition, the sample presents better stability and methanol tolerance than Pt/C in alkaline media. As-obtained interconnected fiber networks facilitate electron and mass transfer to provide more active sites, favorable to the enhancement of electrocatalytic activity. This strategy is also available to prepare other 3D interconnected fiber composites for using in energy and environmental fields.