Bubble Growth and Departure Modes on Wettable/non-wettable Porous Foams in Alkaline Water Splitting
Mar 26, 2021

Congratulations to Ryuichi Iwata, Lenan Zhang, Kyle Wilke, Shuai Gong, and their collaborators in professor Betar Gallant’s group for their recent work on the bubble dynamics in gas-evolving reactions, which was featured on MIT News! In this work, we report the bubble dynamics and overpotential observed during alkaline water splitting on a polytetrafluoroethylene (PTFE) deposited nickel porous electrode. A slight decrease in hydrophilicity induced a drastic transition of bubble dynamics and a significant increase of the transport overpotential. We show that the porous electrode transitioned from a liquid-filled state to a gas-filled state when varying the wettability, which changed the bubble departure sizes and bubble coverage. As a result, there were substantial changes of the transport overpotential. Our work elucidates the fundamental relationship between wettability and water splitting characteristics, which provides a practical scenario for structuring the electrode for gas-evolving reactions. Read more on MIT News, and read the paper here.