Impressed current corrosion toward phase-engineered nickel‑iron layered double hydroxide heterostructures for prominent oxygen evolution reaction.

Under harsh industrial operating conditions, nickel‑iron layered double hydroxides (NiFe-LDH) are beneficial electrocatalysts, but their practical deployment is hindered by insufficient activity and durability. Herein, we report an oxygen vacancy NiFe-LDH/FeOOH heterostructure catalyst with a smaller interlayer spacing and amorphous structure that was prepared using the impressed current corrosion method. The growth of FeOOH was controlled, thereby forming a catalyst with a larger heterogeneous interface area that could increase the active area. At the same time, the hetero-junction and oxygen vacancies induced key electron regulation, thereby significantly enhancing catalytic activity and stability. Moreover, it was found that the impressed current corrosion method can be used to prepare NiFe-LDH catalysts with excellent electron transfer ability, thereby enhancing their catalytic activity and current response speed. In alkaline media, the catalyst delivers outstanding oxygen evolution reaction (OER) performance at 1000 mA cm-2, requiring only 309 mV overpotential and maintaining stability for 14,000 h (more than one year). Additionally, in the case of current fluctuations, this catalyst can respond quickly and has a durability of 450 h. The preparation method and complete mechanism understanding can provide a guiding basis for the construction of advanced NiFe-LDH electrocatalysts.