An Iron-based Film for Highly Efficient Electrocatalytic Oxygen Evolution from Neutral Aqueous Solution

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Developing efficient electrocatalysts for oxygen evolution is crucial for sustainable energy technologies.
• Iron-based materials are attractive due to their abundance and low cost.
• Electrocatalyst films often require high material loading, impacting efficiency and transparency.

Purpose of the Study:

• To develop an ultrathin, highly efficient, and transparent iron-based electrocatalyst for oxygen evolution.
• To investigate the electrodeposition of iron-based films using cyclic voltammetry.
• To evaluate the catalytic activity and stability of the prepared film in neutral aqueous media.

Main Methods:

• Ultrathin Fe-based film preparation via cyclic voltammetry electrodeposition from an Fe(II) solution.
• Characterization using scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray, and X-ray photoelectron spectroscopy.
• Electrochemical evaluation through controlled potential electrolysis for oxygen evolution reaction (OER) in neutral pH.

Main Results:

• Achieved extremely low Fe loading (12.3 nmol cm⁻²) on indium tin oxide electrodes.
• Demonstrated remarkable activity and stability for oxygen evolution, with a turnover number of 5.2 × 10⁴ and turnover frequency of 1528 h⁻¹.
• Confirmed the formation of Fe-based materials in the Fe(III) oxidation state with high atom efficiency and film transparency.

Conclusions:

• The developed ultrathin Fe-based film is a highly efficient electrocatalyst for oxygen evolution in neutral aqueous solutions.
• Fast and simple cyclic voltammetry electrodeposition enables low catalyst loading, enhancing atom efficiency and transparency.
• This study presents a promising approach for cost-effective and high-performance electrocatalysts for water oxidation.