Efficient tri-metallic oxides NiCo₂O₄/CuO for the oxygen evolution reaction

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Developing efficient and stable electrocatalysts for the oxygen evolution reaction (OER) is crucial for renewable energy technologies.
• Nonprecious, earth-abundant materials are highly sought after to replace expensive noble metal catalysts.
• Nickel-cobalt oxides and copper oxides are promising candidates for OER catalysis.

Purpose of the Study:

• To synthesize and characterize NiCo2O4/CuO nanocomposites for efficient OER in alkaline media.
• To investigate the effect of CuO addition on the morphology and catalytic performance of NiCo2O4.
• To evaluate the stability and electrochemical properties of the developed composite materials.

Main Methods:

• A low-temperature aqueous chemical growth method was employed for nanocomposite synthesis.
• NiCo2O4/CuO composites were loaded onto glassy carbon electrodes via drop casting.
• Electrochemical techniques including cyclic voltammetry, linear sweep voltammetry, and electrochemical impedance spectroscopy (EIS) were utilized.

Main Results:

• The addition of CuO altered the nanostructure from nanowires to porous structures.
• The NiCo2O4/CuO composite (sample 2) exhibited a low OER onset potential of 1.46 V vs. RHE.
• Sample 2 achieved a current density of 10 mA cm-2 at an overpotential of 230 mV and showed 35 hours of durability.
• EIS revealed a low charge transfer resistance of 77.46 ohms for sample 2, indicating favorable OER kinetics.

Conclusions:

• NiCo2O4/CuO nanocomposites are effective, stable, and environmentally friendly electrocatalysts for OER.
• The optimized composite (sample 2) shows significant potential for applications in water splitting and energy storage.
• The facile synthesis method and excellent performance encourage further exploration of these materials.