Rapidly synthesized porous alloy heterostructure catalysts for ultra-low energy water splitting under industrial conditions

Nanoscale. 2024 Oct 31;16(42):19844-19855. doi: 10.1039/d4nr03056g.

Abstract

RANEY® nickel is extensively applied in industrial settings for its low cost and ease of scale-up. Nevertheless, its poor activity and high energy consumption restrict the progress of large-scale hydrogen production. Here, we used a RANEY® nickel substrate combined with a one-step electrodeposition method to prepare porous NiFe@RN bifunctional catalysts. The results show excellent catalytic activity in both the HER and OER, with overpotentials of 93.51 and 248 mV, respectively, at a current density of 100 mA cm-2. In industrial settings, the NiFe@RN assembled dual-electrode electrolyzer requires only 1.68 V to drive a current density of 500 mA cm-2, demonstrating excellent stability for 20 hours. Simultaneously, this study also found that the synergistic effect of Ni0, Fe0, and the NiFeOOH heterostructure can significantly enhance the electrode's catalytic activity and stability. At a current density of 500 mA cm-2, the energy consumption of hydrogen is only 3.998 kW h m-3 H2, which is 19.8% lower than the existing industrial catalysts (4.79 kW h m-3 H2). Compared to the current hydrogen production in factories, producing one million tons of hydrogen is expected to save up to 8.87 billion kW h of energy, achieving ultra-low energy consumption in hydrogen production. The catalyst prepared in this study exhibits remarkable catalytic activity under industrial conditions, reducing the energy consumption of industrial-grade electrolytic water, and provides a new perspective for preparing efficient bifunctional electrocatalysts with porous structures on an industrial scale in the future.