Self‐Supported ZIF‐Derived Co3O4 Nanoparticles‐Decorated Porous N‐Doped Carbon Fibers as Oxygen Reduction Catalyst

Abstract Oxygen reduction is a significant cathodic reaction in the state‐of‐art clean energy devices such as fuel cell and metal–oxygen battery. Here, ZIF‐incorporated hybrid polymeric fibres have been fabricated by using a dual‐phase electrospinning method. These are then transformed into Co 3 O 4 ‐nanoparticle‐decorated porous N‐doped carbon fibres (ZIF‐Co 3 O 4 /NCF) through multi‐step annealing treatment. The resultant ZIF‐Co 3 O 4 /NCF is interweaved into a self‐supported film and can be used as a bi‐functional catalyst for catalysing oxygen reduction in both aqueous and non‐aqueous electrolytes. Electrochemical tests demonstrate that ZIF‐Co 3 O 4 /NCF displays a high catalytic activity for oxygen reduction with a half‐wave potential ( E 1/2 ) of 0.813 V (vs. RHE) and an almost favourable four‐electron reduction pathway in alkaline medium. ZIF‐Co 3 O 4 /NCF catalyst only shows 4 mV negative shift of E 1/2 after 5000 continuous CV cycles. In addition, the ZIF‐Co 3 O 4 /NCF can be applied as the cathode catalyst of non‐aqueous Li–O 2 battery, exhibiting a remarkable ORR activity in LiPF 6 contained 1,2‐dimethoxyethane electrolyte. The excellent electrocatalytic performance of ZIF‐Co 3 O 4 /NCF is probably due to the abundance of active sites of graphitic carbon‐wrapped Co 3 O 4 nanoparticles, as well as the cross‐linked fibrous nitrogen‐doped carbon texture.