Construction of Co3O4/Fe2O3 nanosheets on nickel foam as efficient electrocatalyst for the oxygen evolution reaction

The development of earth-abundant and high-performance electrocatalysts for oxygen evolution reaction (OER) is a very important part for electrochemical water splitting to generate cleanliness and renewable hydrogen. The preparation of heterogeneous nanostructure composite is an effective method to further improve the performance of noble-metal-free catalysts. Herein, heterogeneous nanostructure of Co3O4/Fe2O3@NF electrocatalyst for OER was fabricated by a hydrothermal method and the subsequent oxidation process. The as-prepared Co3O4/Fe2O3@NF presents a unique thin-wall cell structure. Benefiting from the thin-wall cell structure and the synergistic effect between Co3O4 and Fe2O3, as well as the three-dimensionally (3D) conductive feature of the substrate of nickel foam (NF), the Co3O4/Fe2O3@NF electrode demonstrated excellent electrocatalytic activity for OER in alkaline solution. The overpotential is 254 mV at 10 mA cm(-2) current density, the Tafel slope is only 33 mV dec(-1), and the electrode also retained good stability of 24 h at the current density of 20 mA cm(-2). Compared with pristine Co3O4/Fe2O3 (eta(10) = 493 mV), Co3O4@NF = 350 mV) and Fe2O3@NF (eta(10) = 378 mV), the Co3O4/Fe2O3@NF electrode displayed obviously enhanced electrocatalytic performance.