Researchers at Canada’s Dalhousie University are floating a new technology that can both desalinate ocean water and yield thermoelectricity. The low-cost, portable water desalination device is intended to address water scarcity in developing or remote areas.

The floating solar desalination system is based on plasmonic titanium carbide nanoparticles, thermally and chemically stable components that excel at capturing and converting light into heat. In an additional environmental coup, the nanoparticles are derived from used tires. The sourcing of Earth-abundant materials from tires via pyrolysis eliminates the need for more cost-intensive precious metals for this application, rendering the system more economical for deployment.

A thin layer of pyrolytic char incorporated into the plasmonic titanium carbides covers the device’s foam surface, insulating it from cold ocean water and maximizing heat localization. When set afloat, a wicking system brings ocean water up to the foam surface, where it undergoes evaporation by the solar-heated plasmonic materials. With the salt left behind, the water recondenses on the clear plastic dome over the top of the device and is funneled down the sides for collection in a sealed bag.

Field tests in Halifax Harbour produced daily water yields of up to 3.67 l, a record-breaking amount for a passive floating solar still. The still detailed in iScience can simultaneously desalinate and disinfect water at a cost of less than one cent per liter, making it remarkably cost efficient.