Nanocubic-Co3O4 coupled with nitrogen-doped carbon nanofiber network: A synergistic binder-free catalyst toward oxygen reduction reactions

•Three-dimensional nitrogen-doped carbon nanofiber (NCNF) network is constructed.•Nanocubic-Co3O4 coated NCNF composites with hierarchical structures are obtained.•The binder-free NCNF@Co3O4 catalyst exhibits excellent ORR catalytic activity.

High-performance electrocatalysts with excellent catalytic activity and long durability competitive to Pt are urgently necessary for fuel cell development. Here, a novel self-standing membrane of nitrogen-doped carbon nanofibers (NCNF) has been developed, acting as a three-dimensionally networked and conductive template for immobilization of electrochemically active Co3O4 particles. Thus, nanocubic-Co3O4 coated NCNF (NCNF@Co3O4) composite fiber membrane with hierarchical structures is obtained, which subtly combines the synergistic effects between the electroactive nanocubic-Co3O4, efficient surface nitrogen doping and highly conductive NCNF network. Therefore, the NCNF@Co3O4 composite exhibits excellent catalytic activity toward oxygen reduction reactions with positive Epeak potential, high current density and superior durability over the commercial Pt/C catalyst, being a promising noble metal-free catalyst for practical fuel cell applications.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideA novel free-standing membrane of nitrogen-doped carbon nanofiber coupled with nanocubic-Co3O4 (NCNF@Co3O4) has been developed, being a promising noble metal-free electrocatalyst toward oxygen reduction reactions with positive Epeak potential, high current density and superior durability over the commercial Pt/C catalyst.