Amorphous/crystalline NiFe LDH hierarchical nanostructure for large-current-density electrocatalytic water oxidation

• Published in: Journal of alloys and compounds 2024-10, Vol.1002, p.175328, Article 175328
• Main Authors: Li, Yilong, Li, Mingzhe, Xie, Chenxuan, Ling, Ziyu, Lv, Yuzhen, Chen, Kepi
• Format: Article
• Language: English
• Subjects: Amorphous/crystalline interface; Catalytic activity; Large-current-density electrolysis; NiFe LDH; Oxygen evolution reaction
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2024.175328

Amorphous structure shows more catalytic active sites but poor conductivity towards oxygen evolution reaction (OER). Herein, we fabricated a novel three-dimensional (3D) self-supported NiFe layered double hydroxides (LDH) catalytic material with amorphous/ crystalline interface, aiming to obtain both excellent catalytic activity and conductivity. This homogeneous hierarchical structure exhibits a high catalytic activity and robustness, giving the industrially required current density of 1000 mA cm−2 at an ultralow overpotential of 359.8 mV with 240-hour stability in 1 M KOH. In-situ electrochemical tests reveal that the amorphous/crystalline interface boosts the intermediates evolution and OER kinetics, which might be ascribed to considerable active sites and fast charge transfer. Moreover, the 3D structure has unique superhydrophilicity and superaerophobicity, which can further accelerate the electrolyte penetration, facilitate the bubbles desorption from the electrode, enhance mass transport, and thus improve OER performance at large current densities. This work provides a feasible way to develop high-performance electrocatalytic material via constructing homogeneous amorphous/crystalline interface. •Amorphous/crystalline NiFe LDH heterostructure was successfully synthesized.•Heterostructure interface boosts the OER activity and stability of NiFe LDH.•Catalyst yields a low overpotential of 359.8 mV to drive 1000 mA cm-2 in 1 M KOH.•Catalyst exhibits 240-h stability at 1000 mA cm-2 with retention rate of 98 %.