Sunlight-Activated Catalyst New Technology Could Use Sunlight to Break Down ‘Forever Chemicals’

Researchers led by the University of Bath have developed a sunlight-activated catalyst capable of breaking down persistent “forever chemicals” in water. Reported in RSC Advances, the carbon-based photocatalyst targets PFAS and converts them into less harmful substances under neutral environmental conditions.

An international team of scientists led by the University of Bath has developed a new catalyst — a substance that speeds up chemical reactions — that uses sunlight to break down so-called ‘forever chemicals’ prevalent in the environment and known to accumulate in the human body with unknown long-term health effects.

They hope this technology could in the future be scaled up and used to detect or remove these persistent chemicals from the environment.

Published in the journal RSC Advances, the authors report a prototype, easy-to-make carbon-based catalyst which could be used to break down polyfluoroalkyl substances (PFAS), a group of water-repellent and incredibly stable chemicals used in products ranging from non-stick saucepans to make-up.

Since PFAS are very chemically stable, they don’t degrade naturally and they’ve been shown to accumulate in the body, water systems, food chain and the wider environment. It’s not fully known what long-term effects they have on human health and the environment, but some studies have linked them to an increased risk of cancer.

Scientists from the University of Bath worked with colleagues from the University of São Paulo (Brazil), University of Edinburgh (Scotland) and Swansea University (Wales) to develop a photocatalyst based on carbon nitrite combined with a rigid microporous polymer.

The polymer helps bind PFAS to the catalyst, which uses light to break it down into carbon dioxide and fluoride, a chemical found in some toothpastes.

First author of the paper, Dr Fernanda C. O. L. Martins, worked on the project during a 6-month placement at the University of Bath as part of her PhD studies at the University of São Paulo.

She said: “PFAS are used in many different products, from waterproof clothing to lipstick, but they accumulate in the body and in the environment over time, with toxic effects.

As well as using it to break down PFAS, the technology could also be used in a sensor for forever chemicals, by detecting the fluoride that is given off. Whilst it is currently at the prototype stage, and the research team is now looking for industrial partners to scale up and optimise the technology.

Professor Frank Marken, from the University of Bath’s Department of Chemistry and Institute of Sustainability and Climate Change (ISCC), led the project. He said: “Currently it’s very difficult to detect PFAS, requiring expensive equipment in a specialist lab.

“We hope that our technology could in the future be used in a simple portable sensor that can be used outside the lab, for example to detect where there are higher levels of PFAS in the environment.”

Original Article: Intrinsically microporous polymer (PIM-1) enhanced degradation of heptadecafluoro-1-nonanol at graphitic carbon nitride (g-C3N4); RSC Advances; DOI:10.1039/D5RA07284K

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