Unlocking the Cu-Co Interplay: Electrodeposited Spinel Co₂CuO₄ as a High-Performance Hydrogen Evolution Catalyst

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Developing efficient electrocatalysts is crucial for sustainable energy conversion.
• Spinel-type oxides are promising for the hydrogen evolution reaction (HER).

Purpose of the Study:

• To fabricate and evaluate spinel-type Co2CuO4 and Co3O4 nanosheet electrodes for alkaline HER.
• To investigate the effect of copper substitution on the catalytic activity and stability.

Main Methods:

• Electrodeposition of Co2CuO4 and Co3O4 nanosheets on Ni foam.
• Electrochemical evaluation of the hydrogen evolution reaction in 1.0 M KOH.
• Structural and surface analyses (e.g., XRD, SEM, TEM).

Main Results:

• Phase-pure, porous, interconnected nanosheet architectures were formed.
• Co2CuO4 exhibited superior HER activity (127 mV overpotential at 10 mA cm-2) compared to Co3O4 (176 mV).
• Co2CuO4 demonstrated excellent stability for 100 hours and improved kinetics.

Conclusions:

• Copper substitution in Co3O4 optimizes electronic structure, enhancing HER performance.
• Co2CuO4 is a promising, durable electrocatalyst for alkaline water electrolysis.
• The nanosheet architecture facilitates gas release and electrolyte diffusion, improving stability.