Handily etching nickel foams into catalyst-substrate fusion self-stabilized electrodes toward industrial-level water electrolysis

Abstract

The key challenge of industrial water electrolysis is to design catalytic electrodes that can stabilize high current density with low power consumption (i.e., overpotential), while industrial harsh conditions make the balance between electrode activity and stability more difficult. Here we develop an efficient and durable electrode for water oxidation reaction (WOR), which yields a high current density of 10000 A m-2 at an overpotential of only 284 mV and shows robust stability even in 6 M KOH strong alkaline electrolyte with elevated temperature up to 80 °C. This electrode is fabricated from cheap nickel foam (NF) substrate through a simple one-step solution etching method, resulting in the growth of ultrafine phosphorus doped nickel-iron (oxy)hydroxide (P-NiFeOOH) nanoparticles embedded into abundant micropores on surface, featured as a self-stabilized catalyst-substrate fusion electrode. Such self-stabilizing effect fastens highly active P-NiFeOOH species on conductive NF substrate with significant contribution to catalyst fixation and charge transfer, realizing a win-win tactics for WOR activity and durability at high current densities in harsh environments. This work affords a cost-effective WOR electrode that can well work at large current densities, suggestive for rational design of catalyst electrodes toward industrial-scale water electrolysis.