Spin Polarization and Phase Transformation-Aided Efficient Overall Water Splitting Using Ni₅₀Mn₁₈Ga₂₅Cu₇...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Ferromagnetic shape memory alloys (FSMAs) exhibit unique phase transitions.
• Nickel-based alloys are explored for catalytic applications.
• Water splitting is a key process for hydrogen production.

Purpose of the Study:

• To investigate the synergistic catalytic effect of half-metallic and shape memory properties in Ni50Mn18Ga25Cu7 (NMGC) alloy for water splitting.
• To evaluate the electrocatalytic performance of NMGC in oxygen evolution reaction (OER) and hydrogen evolution reaction (HER).

Main Methods:

• Experimental demonstration of NMGC alloy's catalytic activity.
• Phase transition analysis of NMGC with temperature.
• Electrochemical measurements of OER and HER performance.
• Investigation of magnetic field effects on catalysis.

Main Results:

• NMGC alloy exhibits synergistic catalysis for both OER and HER.
• The martensite phase of NMGC shows superior electrocatalytic performance.
• High current density (414 ± 3.8 mA/cm²) and low overpotentials for OER (220 ± 1.7 mV) and HER (282 ± 2.2 mV) were achieved.
• An external magnetic field significantly reduces OER and HER overpotentials.

Conclusions:

• The combination of half-metallic and shape memory properties in NMGC alloy enables efficient water splitting.
• NMGC is a promising electrocatalyst for OER and HER, with potential applications in hydrogen production.
• Spin and phase engineering in NMGC play a crucial role in enhancing water-splitting kinetics.