High-Performance Electrolytic Oxygen Evolution in Neutral Media Catalyzed by a Cobalt Phosphate Nanoarray.

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Developing efficient electrocatalysts for the oxygen evolution reaction (OER) at neutral pH is critical for sustainable energy technologies.
• Cobalt-based materials are promising OER catalysts, but their performance is often limited by stability and activity in neutral conditions.

Purpose of the Study:

• To synthesize a novel cobalt phosphate nanoarray (Co-Pi NA) catalyst on a titanium (Ti) mesh.
• To evaluate the electrocatalytic performance and stability of the Co-Pi NA/Ti electrode for the oxygen evolution reaction (OER) at neutral pH.

Main Methods:

• Topotactic conversion of cobalt phosphide nanoarray on Ti mesh to cobalt phosphate nanoarray via oxidative polarization.
• Electrochemical characterization including overpotential measurements and long-term stability tests.

Main Results:

• The resulting Co-Pi NA/Ti electrode exhibited exceptionally high OER catalytic activity.
• An overpotential of only 450 mV was required to drive a current density of 10 mA cm⁻².
• The catalyst demonstrated superior long-term electrochemical stability.

Conclusions:

• The 3D nanoarray configuration enhances active site exposure and facilitates electrolyte/oxygen diffusion, leading to excellent catalytic performance.
• The developed Co-Pi NA/Ti electrode is a highly promising candidate for neutral pH OER applications.
• This work presents an effective strategy for designing advanced electrocatalysts through controlled material transformation.