Flaky Co3O4/BCNO composites as efficient and stable catalysts for the oxygen reduction reaction

Abstract

Much effort has been devoted to developing efficient, stable, and low-cost catalysts for the oxygen reduction reaction (ORR). Herein, we prepared flaky Co₃O₄/BCNO composites as efficient ORR catalysts with one step of the precursor sintering method. BCNO nanosheets were obtained by doping C and O elements into hexagonal boron nitride. They can effectively prevent the agglomeration of Co₃O₄ and stimulate the catalytic activity through electronic interactions. The half-wave potential of the Co₃O₄/BCNO catalyst can be up to 0.84 V (vs. RHE) which is superior to those of Co₃O₄ and commercial Pt/C (20%). The Co₃O₄/BCNO composite has a faster kinetic reaction rate with a Tafel slope of 44.9 mV dec⁻¹, which is lower than those of Pt/C (91.85 mV dec⁻¹) and Co₃O₄ (82.6 mV dec⁻¹). The Co₃O₄/BCNO composite catalyst also has excellent stability and good methanol tolerance. The Co₃O₄/BCNO composite-based Zn–air battery exhibits high power density and specific capacity.