Corrosion engineering towards efficient oxygen evolution electrodes with stable catalytic activity for over 6000...

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Nonprecious materials show promise for oxygen evolution reactions but suffer from short catalytic lifetimes.
• Iridium oxide catalysts are effective but expensive.
• Developing stable and active nonprecious catalysts is crucial for energy applications.

Purpose of the Study:

• To develop an energy-efficient, cost-effective, and scalable method for creating highly active and ultrastable electrodes for the oxygen evolution reaction.
• To transform inexpensive iron substrates into advanced catalytic materials.

Main Methods:

• A corrosion engineering method was employed using iron substrates (plate and foam).
• Iron substrates reacted with oxygen in aqueous solutions containing divalent cations (e.g., nickel) at ambient temperature.
• This process formed iron-containing layered double hydroxide nanosheet arrays on the iron substrates.

Main Results:

• The developed method produced electrodes with excellent catalytic activity for the oxygen evolution reaction.
• The electrodes exhibited remarkable stability, retaining activity for over 6000 hours at high current densities (1000 mA cm⁻²).
• The technique avoids the formation of undesirable rust, instead yielding functional layered double hydroxides.

Conclusions:

• The inexpensive and simple manufacturing technique yields highly active and ultrastable electrodes derived from iron substrates.
• This approach offers a viable alternative to precious metal catalysts for the oxygen evolution reaction.
• The developed electrodes show significant potential for long-term use in electrochemical applications.