Nickel-Iron Nitride-Nickel Sulfide Composites for Oxygen Evolution Electrocatalysis

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Efficient electrocatalysts are crucial for oxygen evolution reaction (OER) in water splitting and rechargeable metal-air batteries.
• Heterostructured materials offer enhanced catalytic activity due to high surface area and synergistic electronic effects.

Purpose of the Study:

• To synthesize and characterize a novel nitride-sulfide composite electrocatalyst (FeNi3N-Ni3S2).
• To evaluate the electrocatalytic performance of FeNi3N-Ni3S2 for the oxygen evolution reaction (OER).
• To assess the stability and efficiency of the composite in rechargeable Zn-air batteries.

Main Methods:

• Hydrothermal synthesis followed by nitridation to prepare the FeNi3N-Ni3S2 composite.
• Electrochemical characterization including cyclic voltammetry and chronoamperometry.
• Performance testing in a rechargeable Zn-air battery setup.

Main Results:

• The FeNi3N-Ni3S2 composite exhibited lower electron densities, reducing activation energy for OER.
• Achieved excellent OER performance with a low overpotential of 230 mV and a Tafel slope of 38 mV dec⁻¹.
• Demonstrated superior stability and lower charging voltage in rechargeable Zn-air batteries compared to IrO2.

Conclusions:

• The FeNi3N-Ni3S2 composite is a highly efficient and stable electrocatalyst for OER.
• This material shows significant potential for advancing applications in water splitting and rechargeable metal-air batteries.
• The synergistic effects in the heterostructure contribute to the enhanced catalytic activity.