Interface Electronic Coupling in Hierarchical FeLDH(FeCo)/Co(OH)₂ Arrays for Efficient Electrocatalytic Oxygen...

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• The oxygen evolution reaction (OER) is critical for sustainable energy systems but suffers from sluggish kinetics.
• Two-dimensional transition-metal hydroxides show promise as efficient OER electrocatalysts.

Purpose of the Study:

• To fabricate and characterize novel 2D hierarchical FeLDH(FeCo)/Co(OH)2 arrays for enhanced OER performance.
• To investigate the catalytic active sites and understand the role of interfaces and alloy composition in OER.

Main Methods:

• Fabrication of 2D hierarchical arrays via growing 2D-ZIF-67 on carbon cloth, transforming it to Co(OH)2, and electrodepositing FeLDH(FeCo).
• Electrochemical testing in 1 M KOH to evaluate OER activity and durability.
• Analysis of catalyst interfaces to identify active sites.

Main Results:

• The optimized FeLDH(FeCo)/Co(OH)2 catalyst achieved an overpotential of 242 mV at 10 mA/cm2 and 279 mV at 100 mA/cm2.
• The catalyst demonstrated excellent durability, operating for 100 hours at 20 mA/cm2.
• Interfaces between FeLDH(FeCo) and Co(OH)2 were identified as the active centers, facilitating intermediate oxygen species transfer.

Conclusions:

• Hierarchical bimetallic hydroxide arrays offer a promising strategy for designing highly active and durable OER electrocatalysts.
• The FeCo alloy enhances electron transfer and stability, contributing to improved OER performance.
• Understanding interfacial effects is key to advancing OER catalyst design for sustainable energy applications.