Most people bring a blanket to the beach to soak up the sun — this “blanket” soaks up pollution instead. Researchers at Ohio State University have created a solar-activated “nanomat” that floats on water like a beach mat, but instead of providing comfort, it goes to work cleaning up harmful contaminants.
a,b) Cu-doped TiO2 heat-treated nanofiber blankets, c) SEM image of the nanofiber.
The lightweight, reusable material can clean polluted water and generate power using sunlight. It was described in a recent Advanced Science publication and could provide a low-cost solution for environmental remediation in resource-limited regions.
The technology uses titanium dioxide (TiO₂) nanofibers created through electrospinning, which applies electrical force to a liquid to produce extremely fine fibers. The resulting nanomat can float on water surfaces and harness solar energy to break down contaminants through photocatalysis.
While titanium dioxide is widely used in self-cleaning materials and solar cells, its photocatalytic activity is typically limited to ultraviolet (UV) light — a small portion of the solar spectrum. To improve its effectiveness, the research team incorporated copper into the fiber matrix, enhancing the material’s ability to absorb visible light and increasing its performance in natural sunlight.
The mats can be deployed on rivers, lakes, or reservoirs and reused through multiple cleaning cycles. In lab tests, the copper-enhanced nano mats demonstrated higher efficiency than traditional solar cells in producing power and degrading pollutants.
“These nanomats can be used as a power generator or as water remediation tools,” Gouma said. “In both ways, you have a catalyst with the highest efficiency reported to date.”
Comparable technologies
Several other technologies have explored solar-powered water purification, though most differ significantly in structure or function.
•Solar Water Disinfection (SODIS), for example, uses plastic bottles to disinfect water with UV light. It’s low-tech and effective for killing microbes but doesn’t address chemical pollutants.
•Suspended nanoparticles like TiO₂ or zinc oxide have been used in experimental setups, but they typically require filtration afterward — something Ohio State’s solid, floating mats avoid.
•Other efforts, such as graphene-based filters or floating photoreactors, show promise in specific applications (like desalination or membrane filtration) but may be less adaptable or scalable.
•Notably, the mats may also have future uses in solar hydrogen production, aligning them with research into solar fuel technologies — a potential long-term benefit.
What distinguishes the Ohio State researchers’ approach is the flexibility and multifunctionality of the mats. They combine photocatalysis, reusability, and simple deployment in a single system. “There hasn’t been an easy way to create something like a blanket that you can lay on water and start creating energy,” said Gouma. “But we are the only ones who have made these structures and the only ones to demonstrate that they actually work.”
Next Steps and Potential Impact
Gouma said the research team is optimistic about scaling the mats for broader use, though adoption will depend on interest from industry and nonprofits.
“We have the tools to make them in large quantities and translate them to various industries,” she said. “The only limitation is that it needs someone to take advantage of these abundant resources.”
Beyond cleaning water, the mats may be adapted for additional environmental and energy applications. “This material is completely novel in terms of a new form of nanotechnology,” Gouma said. “It’s really impressive and something that we are very excited about.”
The study was co-authored by Fateh Mikaeilia and Mohammad Mahafuzur Rahaman, with support from the National Science Foundation. The full paper is available in Advanced Science: https://doi.org/10.1002/advs.202502981
