Size Effects on Bubble Dynamics during Photoelectrochemical Water Splitting

Area of Science:

• Physical Chemistry
• Fluid Dynamics
• Electrochemical Engineering

Background:

• Efficient bubble removal from electrodes is crucial for reducing reaction resistance in photoelectrochemical water splitting.
• Bubble coalescence accelerates detachment, but size-dependent dynamics require further investigation.

Purpose of the Study:

• To investigate the effect of bubble size on coalescence dynamics using the Marangoni effect.
• To establish quantitative correlations for bubble detachment, oscillation, and velocity.

Main Methods:

• Utilized the Marangoni effect for noninvasive control of bubble sliding and coalescence.
• Analyzed bubble detachment induced by capillary wave encounters.
• Characterized bubble damping oscillations and detachment velocity using energy conservation principles.

Main Results:

• Established a quantitative correlation between coalescence oscillation time and capillary wave propagation.
• Demonstrated that detached bubbles exhibit damping oscillations with consistent dimensionless periods.
• Found that bubble detachment velocity follows a power law related to surface energy and radius.

Conclusions:

• Bubble size significantly impacts coalescence and detachment dynamics in photoelectrochemical water splitting.
• The Marangoni effect provides a viable strategy for managing bubble behavior.
• Findings offer insights for optimizing electrolysis technology through controlled bubble dynamics.