Revisited electrochemical gas evolution reactions from the perspective of gas bubbles

Electrochemical gas evolution reactions are common but essential in many electrochemical processes including water electrolysis. During these processes, gas bubbles are constantly nucleating on reaction interfaces in electrolyte and consequently exert an impact on catalysts and the performance. In the past few decades, extensive studies have been conducted to characterize bubbles with emerging advanced technologies, manage behaviors of bubbles, and apply bubbles to various domains. In this review, we summarize representative discoveries as well as recent advancements in electrochemical gas evolution reactions from the perspective of gas bubbles. Finally, we end up this review with a profound outlook on future research topics from the combination of experiments and theoretical techniques, non-negligible bubble effects, gravity-free situation, and reactions under practical industrial conditions.