Modification of CoFe Prussian Blue Structure by N₂ Plasma for Enhanced Electrocatalysis.

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Hydrogen production via water electrolysis is crucial for clean energy.
• The oxygen evolution reaction (OER) kinetics are a major bottleneck for electrolyzer efficiency.
• Developing efficient electrocatalysts for OER is essential for advancing hydrogen technology.

Purpose of the Study:

• To develop a novel nitrogen-doped cobalt-iron Prussian blue analog (CoFePBA-N) electrocatalyst.
• To enhance the catalytic activity and durability for alkaline water and seawater electrolysis.
• To investigate the role of plasma treatment in catalyst morphology and electronic structure modification.

Main Methods:

• Plasma treatment was used to synthesize nitrogen-doped CoFe Prussian blue analogs with a nanosheet-assembled cubic architecture.
• Electrochemical performance was evaluated through measurements of current density and overpotential in alkaline freshwater, simulated seawater, and natural seawater.
• Durability was assessed by long-term stability tests.

Main Results:

• The optimized CoFePBA-N catalyst achieved high current densities at low overpotentials (e.g., 500 mA cm⁻² at 322 mV in alkaline freshwater).
• Exceptional durability was observed, with stable operation exceeding 300 hours in freshwater and 270 hours in natural seawater.
• Plasma treatment led to morphological reconstruction, nitrogen doping, and vacancies, enhancing active sites and modulating electronic structure.

Conclusions:

• The CoFePBA-N catalyst exhibits superior performance and stability for alkaline water and seawater electrolysis.
• Synergistic effects of nitrogen doping, vacancies, and improved charge transfer contribute to the enhanced catalytic activity.
• This approach offers an effective strategy for optimizing Prussian blue analogs for efficient hydrogen production.