Magnesium supplements are gaining popularity to treat conditions such as insomnia, migraines and constipation. Most magnesium salts are extracted from rocks by crushing and heating them, which requires a lot of energy. Now, researchers reporting in ACS Energy Letters have developed bismuth electrodes that selectively pull magnesium ions from seawater, another abundant source of the element. They say their electrochemical approach could be more sustainable and less expensive than current methods.


