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 Cu 3 P 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∥Cu 3 P 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.