Decomposition of perfluorooctanoic acid photocatalyzed by titanium dioxide: Chemical modification of the catalyst surface induced by fluoride ions

• Published in: Applied catalysis. B, Environmental Vol. 148-149; pp. 29 - 35
• Main Authors: Sansotera, Maurizio, Persico, Federico, Pirola, Carlo, Navarrini, Walter, Di Michele, Alessandro, Bianchi, Claudia L.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 27.04.2014; Elsevier
• Subjects: Carbon; Catalysis; Catalysts; Chemistry; Diffraction; Dissolution; Exact sciences and technology; General and physical chemistry; PFOA; Photocatalysis; Photochemistry; Physical chemistry of induced reactions (with radiations, particles and ultrasonics); Pollution; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Titanium dioxide; X-ray photoelectron spectroscopy; X-rays; XPS; XRD; Pollution; XPS; XRD; Titanium dioxide; PFOA; Photocatalysis; Transition element compounds; Ions; Decomposition; Fluorides; X ray diffraction; Heterogeneous catalysis; Chemical modification; Acids; Photoelectron spectrometry; Titanium oxide; Catalyst; Environmental protection
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2013.10.038

•Photocatalytic treatment of PFOA solutions with TiO2 slurry.•TOC analysis to evaluate the carbon content of the treated PFOA solution.•IC analysis to evidence the photodegradation promoted production of fluoride ions.•XPS and XRD analyses of TiO2 to monitor surface variations promoted by fluoride ions. The degradation of perfluorooctanoic acid (PFOA) in water was investigated both as photolysis and photocatalysis by slurry titanium dioxide. Different surfactant concentrations, the catalyst nature and concentration as well as the irradiation power of the UV lamp were evaluated. The reactions were conducted using merely the natural dissolved oxygen (DO), in order to simulate conditions of non-enriched water, as industrially feasible. The photomineralization of PFOA was monitored by total organic carbon (TOC) analysis and ionic chromatography (IC). Finally, the photocatalytic powder was analyzed at different reaction times by X-ray photoelectron spectroscopy (XPS) and by X-ray powder diffraction (XRD) technique in order to study and interpret the catalyst deactivation phenomena occurred during the treatment.