Co 3 O 4 Nanosheet Arrays on Ni Foam as Electrocatalyst for Oxygen Evolution Reaction

Co3O4 nanosheet arrays on Ni foam (Co3O4 NS/NF) were designed, fabricated, and utilized as electrocatalysts for electrochemical oxygen evolution reaction (OER). The electrocatalytic performance of the Co3O4 NS/NF for OER was systematically evaluated by cyclic voltammetry, linear polarization, and Tafel curve measurements. Compared to the bare Ni foam, free-standing Co3O4 nanosheets, and commercialized Pt/C electrodes, Co3O4 NS/NF exhibits excellent OER activity in water-alkaline electrolyte with low onset overpotential (~ 50 mV), large anodic current density, and excellent durability. The compatible electrocatalytic activity for OER of the Co3O4 NS/NF is attributed to the unique nanosheet structure and the interconnected nanoarrays configuration of Co3O4 that provides plentiful catalytic active sites, in addition to the inherent catalytic activity of Co3O4. The electron transportation capability of the supporter Ni foam makes the composite a potential electrocatalyst for OER.