Self-Supported Hierarchical Nanostructured NiFe-LDH and Cu3P Weaving Mesh Electrodes for Efficient Water Splitting

Highly efficient low-cost electrocatalysts for water splitting have attracted increasing interest in the development of energy storage and conversion. Here, we utilized copper (Cu) weaving mesh to in situ fabricate earth-abundant elements-based integrated electrodes for high performance water splitting, where NiFe layered double hydroxide (NiFe-LDH) ultrathin nanoarrys for oxygen evolution reaction (OER) and Cu3P nanowires for hydrogen evolution reaction (HER) were successfully constructed on the Cu mesh. Notably, large stable current densities are obtained for both OER (600 mA cm–2) and HER (200 mA cm–2) electrodes under low overpotential, which is superior to most of the nanoparticle-based electrodes. The large current density is mainly because of the excellent conductivity and clean surface (binder-free) of the Cu mesh-based electrode, and which is extremely important for industrial application. The prepared integrated electrodes are coupled with a macroscopic porous sieve and microscopic nanostructures. The assembled NiFe-LDH∥Cu3P electrolyzer exhibits a small cell working voltage of 1.72 V under the current density of 10 mA cm–2 at room temperature, as well as long-term stabilities (>10 h) in 1 M KOH. These excellent performances of our earth-abundant elements-based weaving mesh electrode result from their improved charge transfer, surface area, mass transport, and faster kinetics of catalytic reactions.