Exploratory construction of Co/Co3O4-Ni/NiO heterointerface modified macroporous interconnected hollow carbon nanofibers towards efficient and flexible electrocatalysis

Developing high-porosity, flexible non-noble metal oxygen electrocatalysts for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) involving proton coupled electron transfer reaction is of essential importance for improving the efficiency of electrocatalysts. Herein, we propose a novel multilevel structure of Co/Co3O4-Ni/NiO doped macroporous interconnected hollow carbon nanofibers (Co/Co3O4-Ni/[email protected]) as a self-standing and binder-free cathode catalyst for Li-O2 batteries. We employed poly(styrene-co-acrylonitrile) (SAN) as a self-sacrificial template to fabricate hollow nanofibers by coaxial electrospinning and pyrolysis. Furthermore, macroporous interconnected hollow carbon nanofibers were achieved by fine-tuning the particle size of ZIF-8 and electrospinning parameters. Remarkably, as a proof-of-concept application, the Co/Co3O4-Ni/NiO decorated self-standing macroporous interconnected hollow carbon nanofibers (MHCNFs) electrodes exhibited significantly electrochemical performance, including a long-term cyclability (163 cycles) and maximum capacity (16623 mAh/g). This work rationally designs a scalable preparation of Co/Co3O4-Ni/NiO doped macroporous interconnected hollow carbon nanofibers, which provides a new idea for the design of self-supporting and binder-free oxygen electrocatalysts.