China Nonferrous Metallurgy

The bubbles generated during the water electrolysis process can affect the stable operation of the electrolytic cell. Understanding the nucleation, growth, and detachment of bubbles is a prerequisite for effectively managing them. Bubble growth is a mass transfer process through the phase interface. Simulating the evolution of bubbles at the single bubble scale can help us to deepen our understanding of the gas-liquid mass transfer process on the electrode surface, as well as the relationship between bubble generation and its impact on the local flow field and concentration field. This can help achieve the stable operation of the electrolytic cell, reduce energy consumption, and improve current efficiency. Visualizing the growth behavior of single bubbles is essential, and the preparation of microelectrodes is indispensable for this purpose, as microelectrodes can stably and periodically produce individual bubbles. Currently, the main methods for preparing microelectrodes include platinum wire embedded in epoxy resin, photolithography and electrochemical codeposition, nanodisk electrode method, and printed circuit board method. This paper elaborates and analyzes the research status of these microelectrode preparation methods. Experimental conclusions on the preparation of microelectrodes by different scholars differ and require experimental verification. Currently, microelectrode preparation technology still cannot visualize the nucleation stage of bubbles. In the future, the visualization of the nucleation process of bubbles under electrochemical control and the use of faster electrochemical instruments to study the nucleation kinetics of bubbles will be the focus.