Unlocking Peak Efficiency in Anion-Exchange Membrane Electrolysis with Iridium-Infused Ni/NiP Heterojunction Electrocatalysts.

Developing cost-effective, highly efficient, and durable bifunctional electrocatalysts for water electrolysis remains a significant challenge. Nickel-based materials have shown promise as catalysts, but their efficiency in alkaline electrolytes is still lacking. Fascinatingly, Mott-Schottky catalysts can fine-tune electron density at interfaces, boosting intermediate adsorption and facilitating desorption to reduce the energy barrier. In this study, iridium-implanted Mott-Schottky Ni/NiP nanosheets (Ir-Ni/NiP) is introduced, which are delivered from the metal-organic framework and employ them as the bifunctional catalysts for water electrolysis devices. This catalyst requires a small 54 mV overpotential for hydrogen evolution reaction (HER) and 192 mV for oxygen evolution reaction (OER) to reach 10 mA·cm in a 1.0 m KOH electrolyte. Density functional theory (DFT) calculations reveal that the incorporation of Ir atoms with enriched interfaces between Ni and NiP can promote the active sites and be favorable for the HER and OER. This discovery highlights the most likely reactive sites and offers a valuable blueprint for designing highly efficient and stable catalysts tailored for industrial-scale electrolysis. The Ir-Ni/NiP electrode exhibits exceptional current density and outstanding stability in a single-cell anion-exchange membrane electrolyzer.