Photocatalytic activity of TiO2-embedded fluorinated transparent coating for oxidation of hydrosoluble pollutants in turbid suspensions
21st ISFC & ISoFT’15 – Como 2015
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published August 29, 2015
published August 29, 2015
published July 2, 2015
published March 8, 2015
Surface fluorination on TiO2 catalyst induced by photodegradation of perfluorooctanoic acid
Author(s): Sara Gatto, Maurizio Sansotera, Federico Persico, Massimo Gola, Carlo Pirola, Walter Panzeri, Walter Navarrini, Claudia L. Bianchi
Source: Catalysis Today
Volume: 241 Pages: 8-14
Published: Mar (2015)
DOI: 10.1016/j.cattod.2014.04.031
ABSTRACT:
The photoabatement of perfluorooctanoic acid in aqueous solution has been performed with a commercial nano-sized TiO2-based photocatalyst content of 0.66 g/L under an UV irradiation of 95 W/m2. PFOA degradation intermediates were investigated by HPLC-MS and 19F-NMR analysis. Evidences of adegradation mechanism based on two competitive pathways are discussed: photo-redox and beta-scission pathways. Shorter perfluorinated carboxylic acids, CnF2n+1COOH (n = 1-6), as expected degradation intermediates, were identified and their concentration trends over time were determined. The apparent pseudo-first order kinetic constant expressed as rate of PFOA disappearance was also measured: kapp 0.1296 h-1. The influence of fluoride ions on TiO2 surface was analyzed by XPS technique, revealing asurface modification that affects the performances of the catalyst.
published January 24, 2015
Photocatalytic activity of TiO2-embedded fluorinated transparentcoating for oxidation of hydrosoluble pollutants in turbid suspensions
Author(s): Federico Persico, Maurizio Sansotera, Claudia L. Bianchi, Carlo Cavallotti, Walter Navarrini
Source: Applied Catalysis B: Environmental
Volume: 170 Pages: 83-89
Published: Jan (2015)
DOI: 10.1016/j.apcatb.2015.01.033
ABSTRACT:
The photodegradative activity of titanium dioxide immobilized into a multilayered transparent fluoropolymeric matrix was studied. The photoactive coating was developed by applying a TiO2-containing fluorinated ionomeric dispersion and a perfluorinated amorphous polymer in an appropriate sequence directly on the UV source. The multilayered coating photocatalytic activity toward hydrosoluble organic pollutants was evaluated in clear as well as in highly turbid conditions obtained by dispersing barium sulfate microparticles in the polluted solution. Rhodamine B-base was chosen as reference organic pollutant. The photoabatement rates with TiO2-embedded fluorinated coating in clear solution and turbid conditions were 0.0923 min-1 and 0.0546 min-1, respectively. In both clear and turbid conditions, TiO2-embedded transparent coating revealed higher photocatalytic activity than merely dispersed TiO2. This behavior was particularly evident at low pollutant concentrations. In addition, catalyst immobilization prevented TiO2 separation and catalyst losses, allowing the development of a simple and efficientcontinuous apparatus.
published April 27, 2014
Decomposition of perfluorooctanoic acid photocatalyzed by titanium dioxide: Chemical modification of the catalyst surface induced by fluoride ions
Author(s): Maurizio Sansotera, Federico Persico, Carlo Pirola, Walter Navarrini, Alessandro Di Michele, Claudia L. Bianchi
Source: Applied Catalysis B: Environmental
Volume: 148-149 Pages: 29-35
Published: Apr (2014)
DOI: 10.1016/j.apcatb.2013.10.038
ABSTRACT:
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.
published October 31, 2013
Effect of amorphous fluorinated coatings on photocatalytic properties of anodized titanium surfaces.
Author(s): PERSICO F., SANSOTERA M., DIAMANTI M. V., MAGAGNIN L., VENTURINI F., NAVARRINI W.
Source: THIN SOLID FILMS
Volume: 545 Pages: 210-216
DOI:10.1016/j.tsf.2013.08.004
ABSTRACT:
The photocatalytic activity promoted by anodized titanium surfaces coated with different amorphous perfluoropolymers was evaluated. A copolymer between tetrafluoroethylene and perfluoro-4-trifluoromethoxy-1,3-dioxole and two perfluoropolyethers containing ammonium phosphate and triethoxysilane functionalities, respectively, were tested as coating materials. These coatings revealed good adhesion to the anodized titanium substrate and conferred to it both hydrophobicity and oleophobicity. The photocatalytic activity of the coating on anodized titanium was evaluated by monitoring the degradation of stearic acid via Infrared spectroscopy. The degradation rate of stearic acid was reduced but not set to zero by the presence of the fluorinated coatings, leading to the development of advanced functional coatings. The morphological variations of the coatings as a result of photocatalysis were also determined by atomic force microscopy.
http://www.sciencedirect.com/science/article/pii/S0040609013012960#
published August 20, 2013
published July 24, 2013
Fluoritech awarded for Best poster on Sustainability at 17th ESFC
During the 17th European Symposium on Fluorine Chemistry (ESFC) in Paris, the poster ”Decomposition of perfluorooctanoic Acid Photocatalyzed by Titanium Dioxide: Chemical Modification of the Catalyst Surface Induced by Fluoride Ions” with authors F. Persico, M. Sansotera, W. Navarrini, C.L. Bianchi, S. Gatto, C. Pirola, was awarded as Best Poster on Sustainability.
published July 1, 2011
