Three-Dimensional Crystalline/Amorphous Co/Co3O4 Core/Shell Nanosheets as Efficient Electrocatalysts for the Hydrogen...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• The transition to a sustainable hydrogen economy necessitates efficient and affordable electrocatalysts for the hydrogen evolution reaction (HER).
• Current HER catalysts often rely on expensive noble metals, hindering widespread adoption.
• Developing earth-abundant alternatives with high catalytic performance is a critical research objective.

Purpose of the Study:

• To investigate the potential of earth-abundant, low-cost electrocatalysts for the electrochemical hydrogen evolution reaction (HER).
• To design and synthesize novel three-dimensional core/shell nanostructures for enhanced HER activity.
• To evaluate the catalytic performance of these novel materials in an alkaline electrolyte.

Main Methods:

• Synthesis of three-dimensional core/shell Co/Co3O4 nanosheets with a metallic cobalt core and an amorphous cobalt oxide shell.
• Electrochemical characterization of the synthesized nanosheets to assess their performance in the hydrogen evolution reaction (HER).
• Analysis of the core/shell nanostructure to understand the relationship between structure and catalytic activity.

Main Results:

• Achieved a benchmark HER current density of 10 mA cm⁻² at an overpotential of approximately 90 mV in 1 M KOH.
• Demonstrated excellent HER activity attributed to the unique metal/oxide core/shell structure.
• The metallic cobalt core provided high electrical conductivity, while the amorphous cobalt oxide shell offered high catalytic activity.

Conclusions:

• The developed three-dimensional Co/Co3O4 core/shell nanosheets exhibit outstanding HER activity.
• The metal/oxide core/shell architecture is a promising strategy for designing efficient and low-cost electrocatalysts.
• This finding paves the way for fabricating earth-abundant metal oxide electrocatalysts for the hydrogen economy.