Synergistic Reconstruction of Defect-Enriched NiFe-LDH Hierarchical Structures toward Large-Current and Stable Oxygen...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Nickel-iron layered double hydroxide (NiFe LDH) is a leading electrocatalyst for alkaline oxygen evolution reaction (OER).
• Developing NiFe LDH with higher intrinsic activity and more active sites via simple methods remains challenging.

Purpose of the Study:

• To introduce a synergistic reconstruction approach for fabricating defect-enriched NiFe LDH (d-NiFe LDH) with 3D hierarchical structures.
• To enhance the intrinsic catalytic activity and expose more active sites for improved OER performance.

Main Methods:

• In situ synergistic reconstruction of molybdates and phytic acid ligands.
• Fabrication of 2D d-NiFe LDH nanosheets on 1D nanorods, creating a 3D hierarchical structure.

Main Results:

• The d-NiFe LDH exhibited enhanced intrinsic catalytic activity and a greater number of exposed active sites due to its 3D hierarchical structure.
• The electrode achieved excellent OER performance with low overpotentials (204 mV at 10 mA cm⁻² and 282 mV at 500 mA cm⁻²) and remarkable stability (>350 h at 500 mA cm⁻²).
• In a two-electrode system with NiMoN, low voltages (1.47 V at 10 mA cm⁻² and 1.73 V at 500 mA cm⁻²) were required.

Conclusions:

• The synergistic reconstruction method effectively produces defect-enriched NiFe LDH with 3D hierarchical structures.
• This approach significantly boosts OER catalytic activity and stability, offering a new strategy for advanced electrocatalyst design beyond OER.