Carbonized-Wood-Supported Ni₃Fe@Ni Core-Shell Nanoparticles as Integrated Catalysts for Highly Efficient Water...

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• The oxygen evolution reaction (OER) is critical for water electrolysis efficiency.
• Sluggish OER kinetics currently limit overall water splitting performance.
• Advanced OER catalysts are imperative for improving electrolyzer efficiency.

Purpose of the Study:

• To synthesize and evaluate novel Ni3Fe@Ni core-shell nanoparticles as OER catalysts.
• To investigate the effect of a unique surface-interior heterostructure on OER performance.
• To demonstrate the potential of surface-interior engineering for catalyst design.

Main Methods:

• Synthesis of ultrafine Ni3Fe@Ni core-shell nanoparticles on a carbonized wood (CW) substrate.
• Electrochemical characterization of the catalyst's overpotential and stability in OER.
• Evaluation of the catalyst in an overall water splitting electrolyzer.
• Analysis of the catalyst's surface-interior heterostructure and its effect on reaction mechanisms.

Main Results:

• Ni3Fe@Ni/CW exhibited a low overpotential of 290 mV at 100 mA cm-2, outperforming other catalysts.
• The catalyst demonstrated excellent long-term stability in both OER and overall water splitting.
• A low cell voltage of 1.74 V at 100 mA cm-2 was achieved in an electrolyzer.
• The surface-interior heterostructure optimized adsorption energetics, shifting the rate-determining step.

Conclusions:

• The developed Ni3Fe@Ni/CW catalyst shows high efficiency and stability for the oxygen evolution reaction.
• Surface-interior engineering is a promising strategy for designing advanced electrocatalysts.
• This approach significantly enhances water electrolysis performance.