Photocatalytic activity of TiO2-embedded fluorinated transparent coating for oxidation of hydrosoluble pollutants in turbid suspensions

21st ISFC & ISoFT’15 – Como 2015

Poster ISFC_f

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21st International Symposium on Fluorine Chemistry & 6th International Symposium on Fluorous Technologies – Como, Italy- August 23-28, 2015

abstract_fedeRELATED POSTER

X INSTM CONFERENCE, Favignana (TP), 28th June – 1st July, 2015

X_INSTM

Surface fluorination on TiO2 catalyst induced by photodegradation of perfluorooctanoic acid

Catalysis Today

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.

Photocatalytic activity of TiO2-embedded fluorinated transparentcoating for oxidation of hydrosoluble pollutants in turbid suspensions

Applied Catalysis B: Environmental

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.

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

Cover image Applied Catalysis B: Environmental

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.

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#

Decomposition of Perfluorooctanoic Acid Photocatalyzed by TiO2: Chemical Modification of the Catalyst Surface Induced by Fluoride Ions.

17th ESFC – Paris 2013

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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.

UV-Resistant Amorphous Fluorinated Coating for Anodized Titanium Surfaces.

7th CoSI 2011 – Noordwijk

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