Free-Sustaining Three-Dimensional S235 Steel-Based Porous Electrocatalyst for Highly Efficient and Durable Oxygen...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• The oxygen evolution reaction (OER) is crucial for energy conversion technologies like water splitting.
• Developing efficient, stable, and cost-effective OER catalysts remains a significant challenge.

Purpose of the Study:

• To prepare and characterize a novel OER catalyst using a modified S235 steel substrate.
• To evaluate the electrocatalytic performance and stability of the modified steel for OER.

Main Methods:

• Facile one-step surface modification of S235 steel via superficial phosphorization.
• Characterization of the resulting 3D interconnected nanoporous surface.
• Electrochemical evaluation of OER activity and stability in alkaline and neutral media.

Main Results:

• The prepared 3D S235-P steel exhibited enhanced OER activity with low overpotential (326 mV at 10 mA cm⁻²) and a small Tafel slope (68.7 mV dec⁻¹).
• The catalyst demonstrated excellent stability and high faradaic efficiency (82.11–88.34%) under long-term operation at pH 13.
• The modified steel also showed stability as an OER electrocatalyst under neutral pH conditions.

Conclusions:

• Superficial phosphorization is an effective method to enhance the OER performance of standard carbon-manganese steel.
• The 3D S235-P steel is a promising low-cost, abundant catalyst for efficient energy conversion.
• The enhanced activity is attributed to the formation of Fe/(Mn) hydroxide/oxohydroxides during the OER process.