Photocatalytic degradation of PFOA : defluorination, toxicity assessment and catalyst regenerationŽener, Boštjan (Avtor) Jamil, Qasim (Avtor) Matoh, Lev (Avtor) Šuligoj, Andraž (Avtor) Kraševec, Ida (Avtor) Papac Zjačić, Josipa (Avtor) Romac, Sandra (Avtor) Kušić, Hrvoje (Avtor) Novak Tušar, Nataša (Avtor) Lavrenčič Štangar, Urška (Avtor) PFOAphotocatalysisdefluorinationtoxicitydegradation intermediatesPer- and polyfluoroalkyl substances (PFAS) represent a large group of over 12000 variants of synthetic fluorine compounds widely used since the 1950s. Owing to their widespread use and the exceptional strength of the C−F bonds, these compounds have started to accumulate in the environment and resist conventional degradation processes. In this work, we investigate the chemical-free photocatalytic degradation and defluorination of perfluorooctanoic acid (PFOA) using platinum-modified titanium dioxide (Pt−TiO$_2$). The effects of various parameters (Pt modification, light intensity and initial PFOA concentration) on photocatalytic efficiency were investigated. The photocatalysts have been extensively characterized, including their structural, morphological, surface-chemical, thermal, and optical properties. LC-MS/MS analysis confirmed breakdown of PFOA molecules by chain-shortening. Although released fluoride ions may contribute to increase in toxicity, the tests show reduced overall toxicity during treatment, confirming environmental relevance. The synthesized Pt−TiO$_2$ demonstrated significantly higher photocatalytic activity under UV-A irradiation compared to commercial P25, achieving up to 99 % parent compound degradation and 50 % defluorination. Calcination of the catalyst removed the adsorbed fluoride species from its surface and restored its activity during reuse.20262026-07-21 10:00:00Neznano185024sl