Enhanced photodegradation of perfluorocarboxylic acids (PFCAs) using carbon quantum dots (CQDs) doped TiO2 photocatalysts: A comparative study between exfoliated graphite and mussel shell-derived CQDs
Makaleler > Tam Makale · 2025
Yazarlar: Mona Nejatpour, Ayşe Merve Ünsür, Bergüzar Yılmaz, Merve Gül, Burcu Ozden, Sibel BARIŞÇI, Meral DÜKKANCI
Journal of Environmental Chemical Engineering, SCI Expanded İndekslerine Giren Dergi, Uluslararası, Wos, 2025, cilt 13, ss 115382-115382
DOI: 10.1016/j.jece.2025.115382
Özet
Remediation of perfluorocarboxylic acids (PFCAs) is crucial due to their widespread distribution, persistence, and harmful effects on aquatic life, especially as short-chain fluorinated compounds are increasingly used as substitutes after the global ban on long-chain PFCAs. This pioneering study explores the photodegradation of perfluorooctanoic acid (PFOA-C8) and several short-chain PFCAs using carbon quantum dot (CQD)-doped TiO₂. We synthesized CQDs via two innovative methods: electrochemical exfoliation of graphite rods (Exfol.CQD) and a hydrothermal process using mussel shell biomass (MCQD). The structural and morphological properties of CQDs, TiO₂, and CQD/TiO₂ composites were characterized. Photodegradation tests showed that Exfol.CQD/TiO₂ significantly improved PFOA degradation under visible light, achieving a twofold increase compared to pure TiO₂. Degradation rates for C3-C6 short-chain PFCAs with Exfol.CQD/TiO₂ ranged from 22 % to 40 %. PFOA decomposed stepwise into shorter-chain PFCAs and F⁻ ions, maintaining excellent reusability after three cycles. In contrast, the MCQD/TiO₂ photocatalyst needed further optimization due to decreased performance. Our research has shown that using pure water and ethanol as electrolytes facilitates the synthesis of high-purity CQDs without the need for chemical additives. This study sheds light on the previously underexplored area of photodegradation of PFCAs via CQD/TiO₂ composites, highlighting their potential applications in wastewater treatment.