Removal of phenanthrene in aqueous solution containing photon competitors by TiO₂-C-Ag film supported on fiberglass

Surface interactions with pollutants and photons are key factors that affect the applications of TiO₂ in environmental remediation. In this study, the solubilizing agents dimethylsulfoxide and polyoxyethylene sorbitan monooleate, which act as photon competitors, had no effect on the photocatalytic activity of TiO₂-C-Ag film in phenanthrene (PHE) removal. Fiberglass with TiO₂-C-Ag coating removed 91.1 ± 5.2 and 99.7 ± 0.4% of PHE in treatments using UVA (365-465 nm) and UVC (254 nm) irradiation, respectively. The use of fiberglass as a support increased the superficial area, thus allowing PHE sorption. C and Ag, which are electrically active impurities in TiO₂, enhanced its photocatalytic activity and thus the attraction of the pollutant to its surface. The use of high-frequency UV light (UVC) decreased the amount of carbon species deposited on the TiO₂CAg film surface. X-ray photoelectron spectroscopy of the TiO₂-C-Ag film revealed extensive oxidation of the carbon deposited on the film under UVC light and loss of electrons from Ag clusters by conversion of Ag⁰ to Ag³⁺.