A Coaxial Three-layer (Ni,Fe)OxHy/Ni/Cu Mesh Electrode: Excellent Oxygen Evolution Reaction Activity for Water Electrolysis
Electrochemical water splitting is restrained by the sluggish oxygen evolution reaction (OER) due to the four-proton-coupled electron transfer. One key strategy for eﬃcient large-scale production of hydrogen by water splitting is to design an electrode structure of low OER overpotential. Herein, a coaxial three-layer structure of OER electrode is constructed by electroplating Ni on Cu mesh and then loading (Ni,Fe)OxHy catalyst via a modified solvothermal method. The obtained coaxial three-layer (Ni,Fe)OxHy/Ni/Cu mesh electrode exhibits excellent OER performance with the overpotentials of 199 and 250 mV at 10 and 50 mA/cm2 and stability for over 72 h in 1 M KOH. The plated Ni layer is critical for the coaxial three-layer (Ni,Fe)OxHy/Ni/Cu mesh structure since it improves stability by preventing Cu from corrosion and meanwhile enhances the adhesive strength of (Ni,Fe)OxHy to the substrate because of the poor crystallinity, which facilitates charge transfer and leads to the extremely low overpotentials. Compared with Ni foam and Ni mesh, Cu mesh is more suitable for high production rate and large-area water splitting at large overpotentials for the excellent conductivity and the lower series electric resistance (Rs). Together with the extremely low cost of Cu mesh, the present coaxial three-layer (Ni,Fe)OxHy/Ni/Cu mesh electrode is promising for the future industrial application.