Micropore-Boosted Layered Double Hydroxide Catalysts: EIS Analysis in Structure and Activity for Effective Oxygen...

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Oxygen evolution reactions (OERs) are critical for energy conversion and storage but require efficient, earth-abundant catalysts.
• Noble metal-based catalysts are effective but costly and scarce.
• Developing cost-effective, high-performance OER electrocatalysts remains a significant challenge.

Purpose of the Study:

• To engineer earth-abundant, noble-metal-free nanomaterials for superior oxygen evolution reaction (OER) electrocatalytic activity.
• To investigate the role of intrinsic properties and defects in layered double hydroxides (LDHs) for OER catalysis.
• To establish a promising model for enhancing OER electrocatalyst activity through defect engineering.

Main Methods:

• A prismlike cobalt-iron layered double hydroxide (Co-Fe LDH) with a 3:1 Co/Fe ratio was synthesized using a facile self-templated strategy.
• The material featured a hierarchical nanoflake shell, interior cavity, and numerous microporous defects.
• Electrocatalytic performance and stability for OER in alkaline media were evaluated, including electrochemical impedance spectroscopy (EIS) analysis.

Main Results:

• The synthesized Co-Fe LDH exhibited a high specific surface area (294.1 m² g⁻¹), providing abundant active sites and enhancing OER kinetics.
• The Co-Fe LDH catalysts demonstrated advanced electrocatalytic performance and remarkable stability for OER.
• EIS analysis confirmed that micropore defects significantly enhance intrinsic catalytic activity, with a much smaller time constant for OER at defects.

Conclusions:

• Engineered microporous defects in Co-Fe LDH play a crucial role in enhancing OER electrocatalytic activity and kinetics.
• The facile self-templated synthesis offers a promising route to earth-abundant, high-performance OER electrocatalysts.
• This work provides valuable insights into defect engineering for improving catalyst performance in energy conversion and storage devices.