Engineering Hierarchically Nano-Structured Cu Foams: Dynamic Hydrogen Bubble Templated Binder-Free Freestanding...

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Designing hierarchical metallic structures for energy devices, sensors, and catalysis is challenging.
• Electrochemical deposition offers pathways for creating complex nanostructures.

Purpose of the Study:

• To develop and investigate the dynamic hydrogen bubble templating (DHBT) approach for fabricating hierarchical copper foams.
• To systematically tune the morphological and surface properties of copper foams by varying DHBT synthesis parameters.
• To demonstrate the application of DHBT-fabricated copper foams as gas diffusion electrodes (GDEs) for CO2 reduction.

Main Methods:

• Utilizing electrochemically generated hydrogen bubbles as dynamic negative templates for copper electrodeposition.
• Investigating DHBT synthesis parameters including current density, time, current modes (direct, pulsed, reversed, alternating), physical conditions (stirring, temperature), and bath composition.
• Fabricating copper foam GDEs using a three-step protocol.

Main Results:

• DHBT successfully produced highly porous hierarchical copper foams with surface nano-structures.
• Morphological descriptors (pore size/density, foam thickness, ECSA, nanoscale features) were systematically tunable via DHBT parameters.
• The fabricated GDEs exhibited promising CO2 reduction performance, achieving high C2+ product selectivity and partial current densities.
• Operational stability of the GDEs was demonstrated over 12 hours.

Conclusions:

• The DHBT approach provides a reproducible and tunable method for fabricating hierarchical copper foams.
• DHBT-derived copper foams are effective for CO2 reduction, showing potential for electrochemical energy conversion applications.
• This study highlights the versatility of DHBT in materials synthesis for targeted applications.