Per- and poly-fluoroalkyl substances (PFAS) have long been scrutinized for harming the planet and the public.
These “forever chemicals” accumulate in the water and soil, eventually building up in the human body through consumption and even skin absorption, linked to a myriad of health concerns as a result. These substances earned their nickname as they’re nearly impossible to get rid of; PFAS decompose only at temperatures exceeding 752 degrees Fahrenheit—almost seven times the maximum heat humans can handle, for reference.
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But now, a team of researchers in Japan claims to have found a way to break down PFAS at room temperature using visible light. The scientists from Ritsumeikan University have devised a defluorination method that may “revolutionize” PFAS treatment.
Their study, published in the journal Angewandte Chemie International Edition last month, details a “photocatalytic method that uses visible light to break down PFAS and other fluorinated polymers (FPs) at room temperature into fluorine ions,” the university said. Using this method, the researchers achieved 100 percent defluorination of perfluorooctanesulfonate (PFOS) within eight hours of light exposure.
“The proposed methodology is promising for the effective decomposition of diverse perfluoroalkyl substances under gentle conditions, thereby significantly contributing toward the establishment of a sustainable fluorine-recycling society,” said Yoichi Kobayashi, lead author of the study and professor in the department of applied chemistry at Ritsumeikan.
The method involves shining visible LED lights on cadmium sulfide (CdS) nanocrystals and copper-doped CdS (Cu-CdS) nanocrystals that are coated with mercaptopropionic acid (MPA) in a solution containing PFAS, FPs and triethanolamine (TEOA). The researchers discovered that this process generates electrons with a high reduction potential, which can break down the strong carbon-fluorine bonds in PFAS molecules.
