Hydrodynamic study of bubble characteristics and bubble rise velocities in batch electrocoagulation with vibration-induced electrode plates using the PIV technique

Effect of Electrolyte pH on Oxygen Bubble Behavior in Photoelectrochemical Water Splitting

“…H 2 and O 2 bubbles often agglomerate on the surface of the cathode and anode in acidic solution. Niza et al found that the bubble size acquired in acid conditions (pH = 5) was smaller than that in basic conditions (pH = 10). In addition, an effective method to predict the interface evolution behavior of gas–liquid two-phase flow by using pressure signals in the flow field has also been developed by researchers. − However, when the electrolyte pH varies over a wide range, how the bubble growth and detachment changes and its effect on the reaction rate are still unclear.…”

“…Many scholars have regulated the force on the bubbles by external interference, adding surfactants, changing irradiation conditions, and modulating the properties of electrolytes to promote bubble detachment and improve reaction efficiency. Niza et al found that the vibration of the electrode prompted the detachment of the bubble, which became smaller when the vibration intensity was 1.8 V compared to the bubble size measured on a fixed electrode plate. Cao et al proposed a way to promote the detachment of bubbles from the TiO 2 electrode surface by external chopping perturbation and found that under rhythmically chopping, the bouncing bubbles grew only when in contact with the anode, and their trajectory approximated a spiral.…”

Study on Bubble Dynamics in Photoelectrochemical Water Splitting with Low-Rate Flow Fields

“…6,7,16,17 In addition to selecting electrodes with better performance, most scholars choose to use reinforcement to enhance the mass transfer effect on the electrode surface, reduce bubble coverage, and improve reaction efficiency. 18,19 Currently, common methods of adding external perturbations include adding a supergravity field, ultrasonic field, magnetic field and vibration, etc. 19−24 Cho et al 24 investigated the electrocatalytic decomposition of water under the influence of ultrasound.…”

“…Various measures have been taken to remove bubbles from the electrode surface. ,,, In addition to selecting electrodes with better performance, most scholars choose to use reinforcement to enhance the mass transfer effect on the electrode surface, reduce bubble coverage, and improve reaction efficiency. , Currently, common methods of adding external perturbations include adding a supergravity field, ultrasonic field, magnetic field and vibration, etc. − Cho et al investigated the electrocatalytic decomposition of water under the influence of ultrasound. It was found that the ultrasonic field promoted bubble fragmentation as well as drift, resulting in a significant decrease in the size of the bubbles retained on the electrode and a significant increase in the current density.…”

“…It was found that the magnetic field parallel to the electrode plane direction can effectively promote the detachment of hydrogen and oxygen bubbles and increase the current. Muhammad Niza et al 19 found that bubbles are more likely to detach when the electrode vibration direction is perpendicular to the electrode plane law by applying vibration to the electrodes; bubbles are more likely to agglomerate when the two directions are parallel, but both of these ways can significantly reduce the bubble coverage without significantly affecting the flow field. Compared with the above methods, the use of the flow field (agitation) to remove bubbles is not only inexpensive and easy to implement but also can achieve good results.…”