Photocatalytic low-temperature defluorination of PTFE.

A visible-light photocatalytic protocol defluorinates PTFE under mild conditions, producing soluble fluoride salts and defluorinated amorphous carbon, with fluoride recoverable as potassium fluoride.

• Why it matters: PTFE’s chemical and thermal stability makes it persistent, while conventional degradation (e.g., pyrolysis above 500 °C or alkali-metal treatment) is energy-intensive, motivating milder recycling methods.
• What they did: Finely divided PTFE powder (~1-μm particle size, 20-mg scale) is dispersed with carbazole-based photocatalysts (CBZ6 and KQGZ), base, and a sacrificial reductant under purple LED irradiation, with fluoride measured by 19F NMR or ion chromatography.
• The result: The reaction yields fluoride salts and carbon-derived oxyanions, and the defluorinated amorphous carbon is characterized by Raman (with XPS, solid-state NMR, and IR support), with the full workflow completed in 189 h (59 h hands-on).

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