title: Photocatalytic degradation of contaminants of concern with composite NF-TiO2 films under visible and solar light.
abstract: This study reports the synthesis and characterization of composite nitrogen and fluorine co-doped titanium dioxide (NF-TiO(2)) for the removal of contaminants of concern in wastewater under visible and solar light. Monodisperse anatase TiO(2) nanoparticles of different sizes and Evonik P25 were assembled to immobilized NF-TiO(2) by direct incorporation into the sol-gel or by the layer-by-layer technique. The composite films were characterized with X-ray diffraction, high-resolution transmission electron microscopy, environmental scanning electron microscopy, and porosimetry analysis. The photocatalytic degradation of atrazine, carbamazepine, and caffeine was evaluated in a synthetic water solution and in an effluent from a hybrid biological concentrator reactor (BCR). Minor aggregation and improved distribution of monodisperse titania particles was obtained with NF-TiO(2)-monodisperse (10 and 50 nm) from the layer-by-layer technique than with NF-TiO(2) +monodisperse TiO(2) (300 nm) directly incorporated into the sol. The photocatalysts synthesized with the layer-by-layer method achieved significantly higher degradation rates in contrast with NF-TiO(2)-monodisperse titania (300 nm) and slightly faster values when compared with NF-TiO(2)-P25. Using NF-TiO(2) layer-by-layer with monodisperse TiO(2) (50 nm) under solar light irradiation, the respective degradation rates in synthetic water and BCR effluent were 14.6 and 9.5 × 10(-3) min(-1) for caffeine, 12.5 and 9.0 × 10(-3) min(-1) for carbamazepine, and 10.9 and 5.8 × 10(-3) min(-1) for atrazine. These results suggest that the layer-by-layer technique is a promising method for the synthesis of composite TiO(2)-based films compared to the direct addition of nanoparticles into the sol.
authors: Department of Chemical Engineering, Complutense University of Madrid, Avda. Complutense, s/n, 28040, Madrid, Spain. hbarndok@quim.ucm.es
authors: H
authors: H
authors: Barndõk
authors: M
authors: M
authors: Peláez
authors: C
authors: C
authors: Han
authors: W E
authors: WE
authors: Platten
authors: P
authors: P
authors: Campo
authors: D
authors: D
authors: Hermosilla
authors: A
authors: A
authors: Blanco
authors: D D
authors: DD
authors: Dionysiou
mesh_terms: D001280:Atrazine / Q000378:metabolism; D002110:Caffeine / Q000378:metabolism; D002220:Carbamazepine / Q000378:metabolism; D002384:Catalysis; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles / Q000737:chemistry; D009584:Nitrogen / Q000737:chemistry*; D010782:Photolysis; D013472:Sunlight; D014025:Titanium / Q000737:chemistry; D062065:Wastewater / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: D001280:Atrazine; D002110:Caffeine; D002220:Carbamazepine; D009584:Nitrogen; D014025:Titanium; D062065:Wastewater; D014874:Water Pollutants, Chemical; C009495:titanium dioxide