title: Visible light caffeic acid degradation by carbon-doped titanium dioxide.
abstract: The removal of the phenolic compound, caffeic acid, by photodegradation has been investigated using carbon-doped titanium dioxide particles as a photocatalyst under visible light. UV-vis absorption spectroscopy and gas chromatography-ion trap mass spectrometry analyses revealed a substrate concentration dependence of the removal of caffeic acid from a water solution. The k2 and t(0.5) parameters of each reaction were calculated by fitting kinetics data to a second-order kinetic adsorption model. To evaluate the photodegradation event, the effect of the adsorption process on the whole degradation was also monitored in the absence of light. Adsorption isotherm studies supported by ζ potential and scanning electron microscopy data demonstrated the pivotal role of the absorption mechanism. It was found that the whole photodegradation process is governed by a synergic mechanism in which adsorption and photodegradation are involved. This study, centered on the removal of caffeic acid from aqueous solutions, highlights the potential application of this technology for the elimination of phenolic compounds from olive mill wastewater, a fundamental goal in both the agronomical and environmental fields.
authors.affiliation: †Consorzio per lo Sviluppo Industriale della Valle del Biferno (COSIB), 86075 Termoli, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Venditti
authors.affiliation: ‡Department of Agricultural, Environmental and Food Sciences (DiAAA) and Center for Colloid and Surface Science (CSGI), Università degli Studi del Molise, Via De Sanctis, I-86100 Campobasso, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Cuomo
authors.affiliation: ‡Department of Agricultural, Environmental and Food Sciences (DiAAA) and Center for Colloid and Surface Science (CSGI), Università degli Studi del Molise, Via De Sanctis, I-86100 Campobasso, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Ceglie
authors.affiliation: §Air Chemical Laboratory, DIPIA, INAIL Settore Ricerca, Via IV Novembre 144, 00187 Rome, Italy.
authors.forename: Pasquale
authors.initials: P
authors.lastname: Avino
authors.affiliation: ‡Department of Agricultural, Environmental and Food Sciences (DiAAA) and Center for Colloid and Surface Science (CSGI), Università degli Studi del Molise, Via De Sanctis, I-86100 Campobasso, Italy.
authors.forename: Mario Vincenzo
authors.initials: MV
authors.lastname: Russo
authors.affiliation: ‡Department of Agricultural, Environmental and Food Sciences (DiAAA) and Center for Colloid and Surface Science (CSGI), Università degli Studi del Molise, Via De Sanctis, I-86100 Campobasso, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Lopez