Tailoring coordinated steps with Ni-substituted Co₃O₄ asymmetric active unit for durable and efficient acidic water...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Developing efficient electrocatalysts for the oxygen evolution reaction (OER) in acidic media is crucial for energy applications.
• Non-noble metal-based catalysts are highly sought after due to cost and abundance, but achieving high activity and stability remains a challenge.

Purpose of the Study:

• To design and synthesize a robust, non-noble metal electrocatalyst for acidic OER.
• To investigate the structure-activity relationship and reaction mechanism of the developed catalyst.

Main Methods:

• Synthesis of Ni-substituted Co3O4 catalyst.
• Electrochemical characterization including overpotential and stability testing.
• In-situ characterizations and Density Functional Theory (DFT) calculations.

Main Results:

• The Ni-substituted Co3O4 catalyst exhibited an overpotential of 334 mV at 10 mA cm⁻² and stability exceeding 130 hours.
• Asymmetric active Co-O-Ni coordination and strong electron coupling enhanced electron transfer and catalytic activity.
• DFT calculations and in-situ data revealed suppressed lattice oxygen involvement and adherence to the adsorbate evolution mechanism (AEM).

Conclusions:

• The developed Ni-substituted Co3O4 is an efficient noble metal-free electrocatalyst for acidic OER.
• Modulating hydroxyl (*OH) coverage is a key strategy for designing high-performance OER catalysts.
• This work provides fundamental insights into catalyst design for improved OER kinetics and stability.