The behavior of bubbles on a rotating ring-disk electrode (RRDE) during water electrolysis has been investigated as fundamental study to evaluate gas evolution reaction electrode activity. The gas evolved on the surface of the electrode reduced the active surface area and increased the overpotential for electrolysis. We investigated how the shape of the electrode affects the bubble behavior and how to obtain an optimal non-blockage electrode surface using a Pt rotating ring disk electrode (RRDE). Standard deviation (SD) of the electrolysis currents was obtained. The value of the SD is corelated with the bubble detachment phenomenon. We found that the rotation induced flux field removes the generated bubble with decrease of the SD. So, a larger SD indicates the bubble accumulation on the electrode surface, and the surface stranding in the gas film. The ring electrode showed higher current with smaller SD than disk electrode at an overpotential for both oxygen and hydrogen evolution reaction. Therefore, a ring electrode is better than a disk electrode to evaluate gas evolution reaction. The optimum current measurement condition is using ring electrode under rotation speed higher than 2500 rpm, because dependence of current and the SD on rotating speed was small enough. Under this condition, HER at − 0.1 V, the ring electrode delivers − 260 mA cm⁻², and the disk delivers − 160 mA cm⁻². For OER at 2.2 V, the ring electrode delivers 195 mA cm⁻², and the disk electrode delivers 130 mA cm⁻². The ring electrode capture about 35% more current than disk, which might be loss by the effect of the bubble blockage. In order to get better current measurement in a gas evolution reaction, using ring electrode to remove the bubbles from the electrode surface in a high rotation speed is recommended.

Graphical Abstract

在水电解过程中，气泡在旋转环盘电极（RRDE）上的行为已被研究为评估气体发生反应电极活性的基础研究。在电极表面放出的气体减少了有效表面积，并增加了电解的过电势。我们研究了电极的形状如何影响气泡行为，以及如何使用Pt旋转环盘电极（RRDE）获得最佳的无堵塞电极表面。获得了电解电流的标准偏差（SD）。SD的值与气泡脱离现象相关。我们发现，旋转感应通量场随着SD的减小而消除了生成的气泡。因此，较大的SD表示气泡在电极表面上的积累，并且表面在气膜中绞合。对于氧和氢放出反应，在超电势下，环形电极显示出比圆盘电极更高的电流，而SD较小。因此，在评估气体逸出反应方面，环形电极优于圆盘电极。电流测量的最佳条件是在转速高于2500 rpm的情况下使用环形电极，因为电流和SD对转速的依赖性足够小。在此条件下，HER在− 0.1 V时，环形电极输出− 260 mA cm 因为电流和SD对转速的依赖性很小。在此条件下，HER在− 0.1 V时，环形电极输出− 260 mA cm 因为电流和SD对转速的依赖性很小。在此条件下，HER在− 0.1 V时，环形电极输出− 260 mA cm⁻²，并且磁盘输出− 160 mA cm ^-2。对于2.2 V的OER，环形电极提供195 mA cm ^-2，而圆盘电极提供130 mA cm ^-2。环形电极捕获的电流比磁盘多约35％，这可能是由于气泡堵塞的影响而造成的。为了更好地测量气体逸出反应中的电流，建议使用环形电极以高转速除去电极表面的气泡。

图形概要