In-situ synthesis of hierarchical NiFe-LDH/NiO nanoflowers on nickel foam as bifunctional catalyst for overall water splitting

The morphology of electrocatalysts play essential roles on water splitting. Herein, Nickel Iron Layered Double Hydroxide (NiFe-LDH)/NiO nanoflowers with hierarchical structure were successfully constructed via an in-situ oxidation and hydrothermal growth method. The assembled hierarchical structure exhibited impressive performance as a bifunctional catalyst for electrocatalysis water splitting, with low overpotentials of 196 mV (@ 10 mA cm −2 ) and 1.64 V (@ 10 mA cm −2 ) for OER and overall water splitting , respectively. Specifically, the hierarchical structure exposed large electrochemically active surface area, providing sufficient active sites for water splitting, and exhibited super hydrophilicity , boosting its contact with electrolytes and the desorption of evolved gas. In addition, the tight interfacial combination among Ni foam substrate, NiO, and NiFe-LDH could reduce the charge transfer resistance to only 6.54 Ω. This work offers a new strategy for designing high-performance Ni-based layered double hydroxide hierarchical structure.