The influence of dissolved gas supersaturation on bubble detachment from planar (photo)electrodes
Feng Liang, Roel van de Krol, Fatwa F. Abdi
Abstract
In this study, we explore the detachment process of oxygen bubbles from a (photo)electrode, with a focus on the often-overlooked influence of a supersaturated boundary layer of dissolved oxygen near the (photo)electrode surface. Numerical simulations were performed to examine subtle changes of the shape of the bubbles at the bubble-electrolyte interface. The presence of the supersaturated boundary layer is found to distort the interface and facilitate bubble detachment by reducing the surface tension force. Parametric investigation of various factors, such as supersaturation levels, boundary layer thickness, electrolyte flow rate, and contact angle were performed to understand how they affect bubble detachment. Surface tension forces are found to dominate bubble detachment behavior over buoyancy, and the solutal Marangoni effect induced shear forces. Based on these findings, several practical engineering considerations for minimizing bubble-induced losses in (photo)electrochemical devices are discussed.