Ni_0.67Fe_0.33 Hydroxide Incorporated with Oxalate for Highly Efficient Oxygen Evolution Reaction

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• The oxygen evolution reaction (OER) is a critical bottleneck in electrochemical water splitting due to its high energy barrier.
• Developing efficient, stable, and cost-effective electrocatalysts for OER is an ongoing scientific challenge.

Purpose of the Study:

• To present a facile synthesis of villi-shaped Ni-Fe hydroxides for enhanced OER performance.
• To investigate the synergetic effects of atomic-level Ni-Fe ratio optimization on electrocatalytic activity.

Main Methods:

• Synthesis of Ni-Fe hydroxides via in situ precipitation from Ni-Fe oxalate precursors.
• Electrochemical characterization of the synthesized materials for OER performance evaluation.
• Analysis of the electronic structure and active sites to understand performance enhancement.

Main Results:

• The optimized Ni-Fe hydroxide electrode demonstrated significantly improved OER kinetics compared to monometallic Ni(OH)2 and Ni foam.
• Achieved a low overpotential of 277 mV at 100 mA cm-2 with excellent long-term stability.
• The enhanced performance is attributed to atomic-level Ni-Fe synergy, increased surface area, and reduced charge transfer resistivity.

Conclusions:

• The facile synthesis approach yields highly active and stable OER electrocatalysts.
• Atomic-level tuning of Ni-Fe ratios in hydroxides is a promising strategy for improving water splitting efficiency.
• The developed villi-shaped Ni-Fe hydroxides show great potential for practical electrochemical water splitting applications.