Optimized Bubble Dynamics of 3D-Printed Electrodes for Enhanced Water Splitting.

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Sluggish gas evolution in water electrolysis hinders catalyst performance by blocking active sites.
• Efficient bubble detachment and transport are crucial for optimizing water electrolysis efficiency.

Purpose of the Study:

• To develop novel three-dimensional (3D)-printed nickel (3DPNi) electrodes with enhanced surface roughness and ordered flow channels.
• To improve bubble dynamics, specifically detachment and transport, for superior catalytic performance in water electrolysis.

Main Methods:

• Fabrication of highly rough 3D-printed Ni electrodes with ordered flow channel structures.
• Characterization of surface properties, including hydrophilic and aerophobic characteristics.
• Electrochemical performance testing for oxygen evolution reaction (OER) and overall water splitting.
• Computational fluid dynamics (CFD) simulations and visual experiments to analyze bubble dynamics.

Main Results:

• The 3DPNi electrodes exhibit enhanced hydrophilic and aerophobic properties, reducing bubble coalescence and accelerating detachment.
• Ordered flow channels effectively prevent bubble trapping, facilitating rapid bubble transport.
• NiFe-LDH coated 3DPNi electrodes achieved a low overpotential of 238 mV at 100 mA cm⁻² for OER.
• The NiFe-LDH/3DPNi electrode demonstrated excellent stability for overall water splitting at 1 A cm⁻², requiring 1.86 V.

Conclusions:

• The developed 3DPNi electrodes with engineered surface roughness and flow channels significantly optimize bubble dynamics.
• This optimization leads to substantially improved catalytic performance and stability for water electrolysis.
• The findings highlight the potential of these advanced electrodes for practical electrochemical applications.