Electrochemical catalysis offers great potential in energy and mass conversion in academy and industry. However, bubble dynamics and its influence on gas-evolving electrode systems remain ambiguous. Detailed information on the local transport process between different phases and the underlying mechanism are required for the full understanding of two-phase flow evolution and distribution. Here, we construct a three-electrode water splitting reaction system to study the bubble dynamics and system efficiency of titanium electrodes with different morphologies. The dynamics of a gas bubble at an electrode with a plate and 100-mesh, 150-mesh, and 300-mesh structures is systematically investigated with respect to applied voltage conditions. Parameters and underlying mechanisms that influence the two-phase flow evolution and electrochemical reaction performance are carefully discussed. Finally, the underlying dynamic force balance on the gas bubble is analyzed to illustrate the mechanism and experimental observations. Our study provides insights in gas-evolving electrocatalysis and offers opportunities for the design and fabrication of high-performance electrocatalytic reactors.
Keywords: bubble growth and detachment; bubble nucleation; electrocatalysis; mesh electrode; water splitting.