Co3O4@g-C3N4 supported on N-doped graphene as effective electrocatalyst for oxygen reduction reaction

Oxygen reduction reaction (ORR) is a key component of numerous energy conversion equipment, including metal-air batteries and fuel cells. Reasonably designing high-efficiency non-noble materials as ORR electrocatalysts is crucial for large-scale practical applications. In this work, a calcination-hydrothermal method is used to prepare Co3O4@g-C3N4 (g-C3N4 wrapped Co3O4 nanoparticle) supported on nitrogen doped graphene (NG). The electrochemical activity of composites is estimated by cyclic voltammograms and linear sweep voltammetry in 0.1 M KOH medium. Owing to the positive synergistic role stemming from the Co3O4, g-C3N4, Co-Nx effective sites and N modified graphene in the composite material, the Co3O4@g-C3N4/NG owns positive onset potential of 0.920 V (vs. RHE) and half-wave potential of 0.846 V (vs. RHE), which are superior to onset potential of 0.917 V and half-wave potential of 0.824 V for commercial Pt/C, respectively. Additionally, it also exhibits longer-term stability and stronger methanol resistance comparing with Pt/C. The nonprecious metal catalyst could be used as a hopeful catalyst to substitute commercial Pt/C for ORR.