NiFe Nanoparticle Nest Supported on Graphene as Electrocatalyst for Highly Efficient Oxygen Evolution Reaction

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Cost-effective electrocatalysts are crucial for advancing clean energy technologies like water splitting and rechargeable metal-air batteries.
• The oxygen evolution reaction (OER) is a key process in these energy conversion and storage systems.
• Developing efficient and stable OER electrocatalysts remains a significant challenge.

Purpose of the Study:

• To design and synthesize a novel, cost-effective electrocatalyst for the oxygen evolution reaction (OER).
• To investigate the structural and electrochemical properties of the synthesized catalyst.
• To evaluate the catalyst's performance and stability in alkaline media for potential energy applications.

Main Methods:

• Synthesis of NiFe nanoparticle nests on graphene support (NiFe NNG) using a rapid reduction process with sodium borohydride.
• Characterization of the catalyst's structure and composition.
• Electrochemical evaluation of OER performance, including overpotential and Tafel slope measurements, and long-term stability tests.

Main Results:

• The NiFe NNG catalyst exhibited a low overpotential of 292.3 mV and a Tafel slope of 48 mV dec⁻¹ at 10 mA cm⁻².
• The graphene support significantly enhanced catalytic activity, electron transferability, and electrical conductivity.
• The catalyst demonstrated remarkable stability over extended operation and performance comparable to commercial IrO₂.

Conclusions:

• The synergistic effect between NiFe nanoparticle nests and graphene contributes to the catalyst's high surface area and intrinsic activity.
• The NiFe NNG catalyst presents a promising, cost-effective alternative for OER applications in energy storage and conversion devices.
• This development paves the way for more efficient and sustainable energy solutions.