AgO-Decorated Multi-dimensional Chrysanthemum-like NiCo2O4 Mounted on Nickel Foam as Highly Efficient and Stable Electrocatalysts for Oxygen Evolution Reaction
AgO nanoparticles were successfully integrated into NiCo2O4 nanosheets for enhanced electrochemical catalysis ability and stability in the oxygen evolution reaction (OER). The chrysanthemum-like NiCo2O4/AgO composites mounted on nickel foam (NF) were synthesized by a hydrothermal-calcination method. AgO upgraded the ratio of Co3+/Co2+ and thus regulated the intrinsic activity of the species. The High hierarchical structure of NiCo2O4/AgO composed of 0D AgO nanoparticles, 1D NiCo2O4 needles, 2D NiCo2O4 nanosheets, and 3D chrysanthemum-like bundles grown on NF bestowed the high surface area and mesoporous structure for the easy evolution of O2. Ni atoms in NiCo2O4 originated in situ from NF in the process of AgO formation produced an integrated electrode of active component of NiCo2O4 bound on NF with superb highway for charge transfer. AgO significantly tuned the structure and physicochemical properties of NiCo2O4. As a result, NiCo2O4/AgO/NF exhibited excellent OER performance with an overpotential of 232 mV to obtain a current density of 10 mA∙cm-2 in alkaline electrolyte, and the catalyst had scarce loss of the initial catalyst activity for 50 h and over 5000 cycles. This study provides a pathway for developing high-performance OER electrocatalysts.