The study investigates the dynamics of coalescence-induced bubble departure during water electrolysis, aiming to enhance the efficiency of hydrogen evolution. By using a dual platinum micro-electrode system in 0.5 M H₂SO₄, the researchers systematically examined the effects of electrode distance and cathodic potential on bubble behavior. High-speed imaging and electrochemical analysis revealed that bubble coalescence can lead to earlier departure compared to buoyancy effects alone, resulting in higher reaction rates at constant potential. However, repeated coalescence events with bubbles close to the electrode can drive departed bubbles back to the surface, increasing the current density. This phenomenon is more pronounced at larger electrode separations, where it can increase the mean current up to 2.4 times compared to a single electrode. The study also proposed a model to predict the critical current required for bubble return, which is influenced by the departure velocity and bubble growth rate. Overall, the findings highlight the potential of coalescence-induced dynamics to improve the performance of gas-evolving electrodes in water electrolysis.The study investigates the dynamics of coalescence-induced bubble departure during water electrolysis, aiming to enhance the efficiency of hydrogen evolution. By using a dual platinum micro-electrode system in 0.5 M H₂SO₄, the researchers systematically examined the effects of electrode distance and cathodic potential on bubble behavior. High-speed imaging and electrochemical analysis revealed that bubble coalescence can lead to earlier departure compared to buoyancy effects alone, resulting in higher reaction rates at constant potential. However, repeated coalescence events with bubbles close to the electrode can drive departed bubbles back to the surface, increasing the current density. This phenomenon is more pronounced at larger electrode separations, where it can increase the mean current up to 2.4 times compared to a single electrode. The study also proposed a model to predict the critical current required for bubble return, which is influenced by the departure velocity and bubble growth rate. Overall, the findings highlight the potential of coalescence-induced dynamics to improve the performance of gas-evolving electrodes in water electrolysis.