Bubble growth and detachment modulated synergistically via electrolyte flow intensity and current density

Electrolytic gas evolution involves complex bubble dynamics that directly affect the efficiency of industrial electrolyzers. Electrolyte flow and current density are key factors modulating bubble growth and detachment. This study specifically investigates the synergistic regulation of hydrogen bubble behavior by electrolyte flow intensity and current density, using electrochemical measurements, high-speed imaging, and multiphysics modeling. Experimental and theoretical analyses reveal the dual effect of electrolyte flow on electrolytic gas evolution. A critical Reynolds number (Re_c) demarcates bubble detachment modes: below Re_c, buoyancy dominates and convection inhibits bubble release by enlarging the contact angle via asymmetric tilting, thereby raising the overpotential by 5–30%; above Re_c, flow dominates and reduces both the detachment radius and the overpotential. A Reynolds number-corrected bubble growth law in flowing electrolytes is derived, and a comprehensive force balance model incorporating thermal and solutal Marangoni effects, electrostatic interactions, and flow effect is developed. Bubble detachment radii and voltage estimation across flow regimes are predicted with errors less than 16% and 6.0% respectively. These insights extend to oxygen evolution reactions and provide a framework for optimizing electrolyzers through flow field design.