Solvent-engineered crystalline-amorphous NiFe LDH electrocatalysts with industrial-grade stability for enhanced water oxidation

Oxygen-vacancy-rich amorphous layered double hydroxides (LDHs) exhibit high oxygen evolution reaction (OER) activity due to unsaturated ligand structures modulating the electronic states of active metals. However, high crystallinity ensures stability limits the development of such amorphous catalysts is prevailing consensus, and the fundamental understanding of constructing amorphous/crystalline coexisting LDHs as viable non-precious anode alternatives remains insufficient. Herein, a crystalline/amorphous coexisting NiFe LDH (a/c-NiFe LDH) electrocatalyst was synthesized at room temperature via a facile solvent adjustment strategy. Adding isopropanol modulates nucleation kinetics, tailors the catalyst’s morphology, and confers exceptional resistance to mechanical degradation during the oxygen evolution process. Crucially, solvent conditioning induces an interspersed amorphous structure within the crystalline LDH framework, regulating electron transfer pathways. Simultaneously, abundant oxygen vacancies optimize the electronic structure near unsaturated metal ligands, synergistically enhancing OER performance. Benefiting from these features, the a/c-NiFe LDH catalyst achieves a remarkably low Tafel slope of 29.6 mV dec −1 , surpassing that of commercial IrO 2 (80.5 mV dec −1 ) and exhibiting the lowest reconstruction potential. Furthermore, it demonstrates outstanding stability exceeding 130 h at an industrial-grade current density of 1 A cm −2 in an anion-exchange membrane water electrolyzer. This work provides a novel design of homologous crystalline/amorphous heterojunction OER electrodes and offers effective guidance for industrial applications.