Removal of Gas Bubbles on an Electrode Using a Magnet

Oxygen evolution reaction is an enabling process of energy storage, metal extraction, and nature photosynthesis. Bubble growth on the electrode surface can block the reaction. Here, we present the use of a magnet to remove bubbles from the catalytic sites, reducing the activation overpotential in the electrochemical reaction. The results demonstrate that the directional migration of oxygen or hydrogen bubbles during water electrolysis can be achieved by the magnetic field, uncovering the transport mechanism of gas bubbles in oriented motion induced by Lorentz force and buoyancy. Increase of magnetic strength can speed up bubble shedding especially at large currents, inhibiting dendrite growth of electrodeposited metal. Moreover, the charging threshold would be lowered at the action of isotropy of Ni magnetic domains. Removal of bubbles absorbed at the electrode using the magnet would be beneficial for energy saving, surface quality of electrodeposited metal, and hydrogen production.