Ni-modified FeOOH integrated electrode by self-source corrosion of nickel foam for high-efficiency electrochemical water oxidation

The construction and application of efficient iron oxyhydroxide (FeOOH) is still a challenge in the field of energy conversion. Here, a facile preparation method is developed by directly utilizing commercialized nickel foams (NF) as the nickel source and the supporting framework, as well as the ingenious use of etching effect originating from acidic medium in the process of iron salt hydrolysis. As a result, a Ni-modulated FeOOH integrated electrode (Ni-FeOOH/NF) is obtained. Unexpectedly, the implementation of our scheme effectively activates the catalytic intrinsic activity of FeOOH, successfully transforming the inert NF into an integrated electrode with high oxygen evolution reaction (OER) performance. Specifically, the Ni-FeOOH/NF exhibits the overpotential of 277 mV (@100 mA cm−2) and superior stability for OER. Additionally, the as-prepared Ni-FeOOH/NF electrode could also operate steadily for OER in alkaline adjusted saline water. Our research provides a new idea for the preparation of satisfactory Fe-based metal materials as OER electrocatalysts. A superior electrode for electrocatalytic water oxidation in which Ni-modulated FeOOH catalyst in-situ grown on the NF (Ni-FeOOH/NF) by a simple hydrothermal etching method. [Display omitted] •Ni-reorganized FeOOH nanosheets integrated in-situ on the interconnected and conductive NF substrate (Ni-FeOOH/NF) were successfully fabricated on nickel foam (NF) substrates by a simple self-source corrosion method.•The implementation of our scheme effectively activates the catalytic intrinsic activity of iron oxyhydroxide, successfully transforming the inert NF into an integrated electrode with high OER performance.•Ni-FeOOH/NF shows a promising OER performance with the low overpotential of 277 mV at 100 mA cm−2 and superior stability of 40 h.•The superior OER performance and stability of Ni-FeOOH/NF in the alkaline adjusted saline water could promote the exploration of electrodes for seawater electrolysis in the future.