As water-splitting technologies improve, often using porous electrode materials to provide greater surface areas for electrochemical reactions, their efficiency is often limited by the formation of bubbles that can block or clog the reactive surfaces. Now, a study at MIT has for the first time analyzed and quantified how bubbles form on these porous electrodes. Bubble growth and departure are ubiquitous phenomena in gas-evolving reactions, which govern the overall energy and mass transport. However, an in-depth understanding of the relationship between bubble dynamics and the electrochemical processes, in particular, the wettability effect on a gas-evolving porous electrode remains elusive. Here, 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 […]