Boosting large-current-density water oxidation activity and stability by phytic acid-assisted rapid electrochemical...

Corrosion engineering is an efficient strategy to achieve durable oxygen evolution reaction (OER) catalysts at high current densities beyond 500 mA cm^-2. However, the spontaneous electrochemical corrosion has a slow reaction rate, and most of them need to add large amounts of salts (such as NaCl) to accelerate the corrosion process. In this report, a novel and effective phytic acid (PA)-assisted in situ electrochemical corrosion strategy is demonstrated to accelerate the the corrosion process and form bimetallic active catalysts to show excellent OER performance at large current densities. In situ rapid electrochemical corrosion of nickel foam substrate and PA ligands etching realize localized high concentrations of Ni and Fe ions. High concentrations of metal ions will combine with hydroxyl to effectively form defects-enriched NiFe layered double hydroxides porous nanosheets tightly anchoring on the underneath substrate. Remarkably, the activated electrode exhibits excellent OER catalytic activities with ultralow overpotentials of 289 and 315 mV to reach high current densities of 500 and 1000 mA cm^-2, respectively. When coupled with Ni-Mo-N hydrogen evolution reaction catalysts, the two-electrode cell merely requires 1.87 V to deliver 1000 mA cm^-2. The ligands-assisted rapid electrochemical corrosion strategy provides a fresh perspective for facile, cost-effective, and scale-up production of superior OER catalysts at large current densities.