Three-dimensional macroporous NiCo(2)O(4) sheets as a non-noble catalyst for efficient oxygen reduction reactions

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Developing efficient non-noble metal electrocatalysts is crucial for energy conversion technologies.
• The oxygen reduction reaction (ORR) is a key process in fuel cells and metal-air batteries.
• Macroporous materials offer advantages in mass transport and surface accessibility for catalysis.

Purpose of the Study:

• To develop a facile and low-cost strategy for synthesizing 3D macroporous NiCo2 O4 sheets.
• To evaluate the electrocatalytic performance of these sheets for the oxygen reduction reaction (ORR) in alkaline media.
• To investigate the structure-property relationships governing their catalytic activity.

Main Methods:

• Synthesis of 3D macroporous NiCo2 O4 sheets using a low-cost method.
• Characterization of the material's structure, including thickness and pore volume.
• Electrochemical testing to assess ORR activity, pathway, stability, and methanol tolerance.

Main Results:

• Successfully prepared 3D macroporous NiCo2 O4 sheets with a thickness of approximately 150 nm.
• Achieved high pore volumes (up to 0.23 cm(3) g(-1)), enhancing mass transport.
• Demonstrated high electrocatalytic activity for ORR via a four-electron pathway, with excellent long-term stability and methanol tolerance.

Conclusions:

• The developed 3D macroporous NiCo2 O4 sheets are highly efficient non-noble metal electrocatalysts for ORR.
• The unique 3D macroporous structure significantly contributes to the enhanced catalytic performance.
• This strategy offers a promising route for cost-effective electrocatalyst development.