The function of carbon quantum dots (CQDs) derived from peapod biomass in composite photocatalysts for the enhanced photodegradation of perfluoroalkyl carboxylic acids (PFCAs) under UVC and visible light irradiation
Makaleler > Tam Makale · 2025
Yazarlar: Mona Nejatpour, Bergüzar Yılmaz, Burcu Ozden, Sibel BARIŞÇI, Meral DÜKKANCI
Journal of Water Process Engineering, SCI Expanded İndekslerine Giren Dergi, Uluslararası, Wos, 2025, cilt 73, ss 107750-107750
DOI: 10.1016/j.jwpe.2025.107750
Özet
The remediation of perfluoroalkyl carboxylic acids (PFCAs) presents a significant challenge due to their environmental persistence and detrimental impact. In this study, carbon quantum dots (CQDs) were sustainably prepared using peapod biomass via the hydrothermal method and incorporated into a titanium dioxide (TiO2) composite photocatalyst. Chemical, morphological, and optical analysis confirmed the efficient synthesis of the CQD/TiO2 composite, which exhibited enhanced optical properties. Photocatalytic oxidation experiments demonstrated that the CQD/TiO2 composite achieved significantly higher degradation efficiencies for perfluorooctanoic acid (PFOA-C8) compared to pristine TiO2, with 26.3 % and 24.5 % improvements when irradiated under Ultraviolet-C (UVC) and visible light, respectively. Furthermore, the photocatalytic oxidation of short-chain PFCAs, specifically perfluorohexanoic acid (PFHxA-C6), perfluoropentanoic acid (PFPeA-C5), perfluorobutanoic acid (PFBA-C4), and perfluoropropanoic acid (PFPrA-C3), were evaluated under visible light irradiation. Degradation rates for PFHxA-C6 and PFPeA-C5 significantly enhanced from 14.6 % and 19.6 % to 41.3 % and 52.1 %, respectively, when using CQD-coupled TiO2 (CQD/TiO2) compared to pure TiO2. The first-order rate constants revealed accelerated PFCA degradation using PPCQD/TiO2 photocatalysts. Intermediate formation (C3–C6) and defluorination analyses revealed stepwise decomposition of PFCAs, with enhanced CF₂ detachment in the presence of the CQD/TiO2 composite. The role of scavengers in PFOA degradation under visible light was also examined. This research underscores the potential of CQD-enhanced TiO2 photocatalysts for effective PFCA remediation under sustainable conditions.