Nucleation and growth of electrolytic gas bubbles under microgravity

作者：Sakuma Go; Fukunaka Yasuhiro; Matsushima Hisayoshi^*

来源：International Journal of Hydrogen Energy, 2014, 39(15): 7638-7645.

DOI：10.1016/j.ijhydene.2014.03.059

• Water electrolysis
• Microgravity
• Oxygen gas evolution
• Wettability
• Self-assembled monolayer

The evolution of oxygen gas bubbles in potassium hydroxide solution is observed in situ under microgravity by a charge-coupled device camera, focusing on the wettability of a platinum electrode modified by thiol self-assembled monolayers. Single bubble measurements on the microwire electrode reveal a three-step growth process involving (1) the nucleation and formation of a supersaturated layer of dissolved gas followed by (2) a rapid growth phase depending on the gas diffusion process, and finally, (3) a stable growth phase where the growth rate is dominated by the bubble configuration depending on the contact angle. Moreover, correlation of multiple gas bubble observations with electrochemical data and surface coverage on the plate electrode reinforce the important role of wettability in determining bubble motion and energy consumption during electrolysis under microgravity.

• 出版日期2014-5-15