By Tudor Tarita
Per- and polyfluoroalkyl substances (PFAS) are the ultimate environmental villains. They’re designed to shrug off heat, water, and oil, and they’re excellent at that. But they’re so good that they never really go away. These “forever chemicals” have leached from industrial sites into drinking water across the globe.
Their secret is the carbon–fluorine bond—one of the strongest links in chemistry and a nightmare to break. Most treatments only manage to snap long PFAS molecules into smaller pieces, which then linger in the environment just as stubbornly as their parents. But Chibueze Amanchukwu, a researcher at the University of Chicago, decided to look at the problem through the lens of battery failure.
Drawing on his work in lithium-ion battery chemistry, he and his colleagues asked whether the same reactions that cause batteries to fail could dismantle “forever chemicals” nearly completely.
Turning the Problem on Its Head
At the molecular level, strong carbon–fluorine bonds hold PFAS molecules together and resist breaking. Those bonds give the chemicals their familiar performance traits—resisting flames, grease, and moisture in products ranging from firefighting foams to nonstick pans and protective fabrics. The same chemical strength, however, allows PFAS to survive most attempts to degrade them once they escape into the environment.
For decades, researchers have tried to attack PFAS by oxidation—stripping electrons away until molecules fall apart. But fluorine complicates that strategy.
“Fluorine is the most electronegative element, so it really loves electrons,” Amanchukwu said. “This makes oxidizing fluorinated compounds hard to do. It is much easier to reduce them.”
So, the team tried reduction—shoving extra electrons into the molecule.
Amanchukwu and University of Chicago Pritzker School of Molecular Engineering postdoctoral researcher Bidushi Sarkar hope to apply their technique’s successes to a larger number of the massive “forever chemical” family.
In water, this is nearly impossible because those extra electrons would rather react with the water itself. To bypass this, the team looked to battery science. Inside a lithium battery, the environment is non-aqueous (water-free) and notoriously harsh. It’s an environment where even the toughest fluorinated compounds eventually break down.
The team used copper electrodes onto which lithium metal is electrochemically deposited, a setup familiar to battery researchers. When current flows, freshly deposited lithium transfers electrons directly to PFAS molecules, destabilizing carbon–fluorine bonds and driving the compounds toward collapse.
“The electrochemistry is simply putting electrodes into a solvent,” said George Schatz, a theoretical chemist at Northwestern University and a co-author on the study. “If you have these molecules dissolved into solvents, and then you pass current from the electrodes through the solvent, Chibueze and his team have developed a scheme where that destroys the PFAS.”
A Conceptual Shift
In laboratory tests, the approach proved surprisingly versatile. Of 33 PFAS compounds examined, 22 degraded by more than 70%, with some reaching nearly complete defluorination. The process worked best on long-chain PFAS like PFOA (perfluorooctanoic acid), which are among the most persistent in the environment.
Outside experts see the work as a conceptual shift. Brian Chaplin, a chemical engineer at the University of Illinois Chicago who was not involved in the research, called it “a useful conceptual advance for future reductive PFAS treatment strategies.”
Fluorine is a valuable industrial element, but PFAS lock it into environmentally damaging forms. By breaking PFAS into simple fluoride salts, the researchers opened a path to reusing the fluorine to make new, PFAS-free fluorinated compounds.
However, that circular vision remains far from deployment. We aren’t at a commercial scale yet. The system currently requires specific solvents and controlled conditions that aren’t ready for your local water treatment plant. However, the modular nature of electrochemistry means we could eventually see small, solar-powered reactors cleaning up waste right at the source—no massive, high-pressure plants required.
“The reason people love electrochemistry is that it is quite modular,” Amanchukwu said. “I can have a solar panel with batteries, and I can have an electrochemical reactor on site that is small enough to deal with any local waste streams. You don’t need a large plant that operates at high temperatures or high pressures.”
The team published their work in the journal Nature Chemistry