Hierarchical NiF 2 /CoF 2 Nanoarchitectures on Nickel Foam: Synthesis and Electrochemical Properties

The development of efficient non-precious metal electrocatalysts is crucial for advancing the hydrogen energy industry. In this study, we synthesized NiF 2 /CoF 2 composite materials and investigated their electrocatalytic performance for the oxygen evolution reaction (OER). Structural and morphological characterizations confirmed the successful formation of highly crystalline NiF 2 /CoF 2 nanosheets with a well-defined layered architecture. Electrochemical tests revealed that the NiF 2 /CoF 2 electrode exhibited superior OER activity, demonstrating a low overpotential of 191 mV at 10 mA cm −2 and a Tafel slope of 46.6 mV dec −1 , indicating favorable reaction kinetics. Notably, the NiF 2 /CoF 2 sample displayed a high electrochemical double-layer capacitance (C 5l ) of 0.2228 F cm −2 , suggesting a large electrochemical active surface area (ECSA) and abundant accessible active sites. This enhanced catalytic performance is attributed to the synergistic interaction between NiF 2 and CoF 2 , which facilitates efficient charge transfer and strong adsorption of water molecules. Additionally, the NiF 2 /CoF 2 electrode demonstrated excellent stability during prolonged electrolysis, making it a promising candidate for practical water-splitting applications. This work provides valuable insights into the design of cost-effective and high-performance electrocatalysts for sustainable hydrogen production.