Optimizing electronic structure of NiFe LDH with Mn-doping and Fe_0.64Ni_0.36 alloy for alkaline water oxidation under industrial current density

Alkaline electrolyzers for water splitting under the industrial current densities are always burdened with huge energy consumption due to the high overpotential and poor stability of the anode nanocatalysts for oxygen evolution reaction (OER). Inspired by the interfacial charge transfer for enhancing the performance, a series of in-situ grown interfacial Mn-NiFe lactate dehydrogenase (LDH) was designed on the Fe_0.64Ni_0.36/NM (nickel mesh) alloy layer. The optimized Mn_0.15-NiFe LDH/Fe_0.64Ni_0.36/NM exhibited an ultralow overpotential of 295 mV to drive 500 mA·cm⁻² and an incredible stability under large current density. The interfacial space and heteroatom doping synergistically triggered the electronic structure optimization to promote electron transfer and ensure the durability of the high-current reaction. Notably, the designed Mn_0.15-NiFe LDH/Fe_0.64Ni_0.36/NM as an anode in an integral alkaline electrolyzer exhibited a cell voltage of 1.78 V at 500 mA·cm⁻² with a stability of 366 h. Density functional theory (DFT) calculations further demonstrated the synergistic effect of alloy layer introduction and Mn doping could accelerate electron transfer and stabilize the charged active center to activate the NiFe LDH and reduce the OER energy barrier. Our work offers new insights into developing efficient self-supported catalysts for high-current alkaline water oxidation.