Two new approaches for decomposing poly- and perfluoroalkyl substances (PFAS) using light-activated catalysts in more recyclable byproducts are presented in two articles published in Nature.
PFAS are commonly used in many everyday products due to their durability and resistance to water, oil, stains, and heat.
However, the carbon–fluorine bonds that confer this resistance are difficult to break, which is why PFAS have been dubbed “forever chemicals” due to their persistence in the environment. Current PFAS recycling methods are limited and require strong chemicals or high temperatures.
Yan-Biao Kang and colleagues present a new method to decompose PFAS chemicals using a light-activated catalyst. The catalyst absorbs light and uses this energy to break the strong carbon–fluorine bonds found in PFAS.
The authors found that these reactions can occur at temperatures between 40 °C and 60 °C, and when they tested polytetrafluoroethylene (a type of PFAS), it decomposed into carbon and fluoride salts. Through their analysis, the authors were also able to decompose the perfluorocarbons, the perfluorooctane sulfonic acid and the perfluorooctanoic acid into carbonate, formate, oxalate, and trifluoroacetate.
They suggest that this process allows the fluorine present in the products to be readily recycled in the form of salts. And they note that further investigation is needed into other light-activated catalysts that could be used in this process at relatively low temperatures.
In a second article, Garret Miyake and colleagues propose a different catalyst that absorbs light to decompose the chemicals forever. When paired with tetra-n-butylammonium fluoride, the blue-light-absorbing catalyst can break the carbon–fluorine bonds in PFASs.
The authors state that their system can use readily available chemicals and suggest that it may offer a new way to decompose these persistent chemicals.
