Scalable electrodeposition of NiFe-based electrocatalysts with self-evolving multi-vacancies for high-performance industrial water electrolysis

Water electrolysis is a promising technique for green hydrogen production to achieve the global strategic goal of carbon neutrality. Herein, we propose an optimized-electrodeposition set-up in Ethaline-based deep eutectic solvent (DES) for the electrochemical preparation of NiFe-based catalysts. The developed synthesis procedure involves the anodic dissolution of Fe plates to provide Fe sources, which are gradually incorporated into the in-situ grown Ni films to fabricate NiFe-based electrodes. Our findings show that introducing nitrate ions coupled with electrochemical water oxidation can induce the formation of multi-vacancy-rich NiFe-based catalysts with outstanding water splitting performance in quasi-industrial conditions. A simulated industrial anion exchange membrane (AEM)-based device loaded with our NiFe-based electrocatalysts requires only 1.73 Vcell to reach 1000 mA cm−2 in 5.0 M KOH at 60 °C and works continuously for up to 200 h. The present work provides a means for the scalable synthesis of self-supported NiFe-based catalysts for industrial water splitting. [Display omitted] •NiFe-based catalysts are fabricated via an optimized electrodeposition approach in Ethaline.•High-performance AEM-based device loaded with the prepared NiFe-based catalysts is achieved.•Synergism in the multi-vacancy-rich NiFe-based electrocatalysts is revealed.•It provides a scale-up route to synthesize NiFe-based catalysts for industrial water splitting.