Adsorption of gas bubbles on the electrode surface is one of important issues responsible for the reduced efficiency of water electrolysis. Understanding the bubble phenomena can benefit the management of gas bubbles. In this study, we carried out a single-entity electrochemical study of individual gas bubbles on the Pt electrode using scanning electrochemical cell microscopy. Different from conventional ensemble methods, the bubble nucleation behaviour and the effect of surfactants (perfluorooctanoic acid (PFOA), hexadecyl trimethyl ammonium bromide (CTAB) and siloxane defoamer) on the electrode surface were investigated at microscale resolution. Statistical analysis of individual nucleation event showed the stochastic characteristic and the addition of surfactant could significantly improve the stability of gas bubbles especially those formed in small nanopipets. A correlation between the critical supersaturation (or Faradic current) for bubble nucleation and surface tension with was observed, which was consistent with classic nucleation theory. However, chronoamperometry study showed that the water electrolysis efficiency after surfactant addition was not significantly improved. This study provided unique insights into understanding of nucleation event at single-entity.

气泡在电极表面的吸附是导致水电解效率降低的重要问题之一。了解气泡现象可以有益于气泡的管理。在这项研究中，我们使用扫描电化学电池显微镜对Pt电极上的单个气泡进行了单实体电化学研究。与常规的整体方法不同，以微米级分辨率研究了气泡成核行为和表面活性剂（全氟辛酸（PFOA），十六烷基三甲基溴化铵（CTAB）和硅氧烷消泡剂）的作用。对单个成核事件的统计分析表明，其随机性和表面活性剂的添加可以显着提高气泡的稳定性，尤其是在小型纳米吸管中形成的气泡。观察到气泡成核的临界过饱和度（或法拉第电流）与表面张力之间的相关性，这与经典成核理论是一致的。然而，计时电流法研究表明，添加表面活性剂后的水电解效率没有显着提高。这项研究为理解单个实体的成核事件提供了独特的见解。计时电流法研究表明，加入表面活性剂后水电解效率没有明显提高。这项研究为理解单个实体的成核事件提供了独特的见解。计时电流法研究表明，加入表面活性剂后水电解效率没有明显提高。这项研究为理解单个实体的成核事件提供了独特的见解。