Enhancing Hydrogen Evolution Reaction through Coalescence-Induced Bubble Departure on Patterned Gold-Silicon...

Area of Science:

• Electrochemistry
• Materials Science
• Chemical Engineering

Background:

• Hydrogen bubble adhesion impedes efficient hydrogen evolution reaction (HER) by increasing overpotential and reducing reaction efficiency.
• Current strategies often rely on micro/nanostructured surfaces for buoyancy-driven bubble detachment.

Purpose of the Study:

• To investigate the impact of surface wettability and patterning on bubble dynamics and HER performance.
• To explore coalescence-induced bubble departure as an alternative to buoyancy-driven detachment.

Main Methods:

• Fabrication of patterned gold-silicon microstrip (GSM) surfaces with varying gold strip widths (50-1600 μm).
• Systematic study of bubble adhesion, departure diameter, and departure frequency on these patterned surfaces.
• Evaluation of HER performance and transport overpotential at different current densities.

Main Results:

• Reduced gold strip width on GSM surfaces led to smaller bubble departure diameters and increased departure frequencies.
• A 400 mV reduction in transport overpotential was observed at 400 mA/cm² on 50 μm wide GSM surfaces.
• Patterned surfaces showed improved HER performance over plain gold surfaces, even with reduced active area.

Conclusions:

• Introducing nonreactive, hydrophilic surfaces promotes coalescence-induced bubble departure, enhancing HER.
• Optimized surface patterning (200 μm gold strips) balances bubble dynamics and reaction area for superior HER performance.
• This approach offers a novel strategy to mitigate bubble adhesion issues in electrochemical hydrogen production.